<?xml version="1.0" encoding="us-ascii"?>
<!--XBRL document created with Toppan Merrill Bridge  9.6.0.116 -->
<!--Based on XBRL 2.1-->
<!--Created on: 5/7/2020 2:55:17 PM-->
<!--Modified on: 5/7/2020 2:55:17 PM-->
<linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DocumentDocumentAndEntityInformation" roleURI="http://www.ardelyx.com/role/DocumentDocumentAndEntityInformation" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#StatementCondensedBalanceSheets" roleURI="http://www.ardelyx.com/role/StatementCondensedBalanceSheets" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#StatementCondensedBalanceSheetsParenthetical" roleURI="http://www.ardelyx.com/role/StatementCondensedBalanceSheetsParenthetical" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#StatementCondensedStatementsOfOperationsAndComprehensiveLoss" roleURI="http://www.ardelyx.com/role/StatementCondensedStatementsOfOperationsAndComprehensiveLoss" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#StatementCondensedStatementsOfChangesInStockholdersEquity" roleURI="http://www.ardelyx.com/role/StatementCondensedStatementsOfChangesInStockholdersEquity" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#StatementCondensedStatementsOfCashFlows" roleURI="http://www.ardelyx.com/role/StatementCondensedStatementsOfCashFlows" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureOrganizationAndBasisOfPresentation" roleURI="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentation" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureCashCashEquivalentsAndShortTermInvestments" roleURI="http://www.ardelyx.com/role/DisclosureCashCashEquivalentsAndShortTermInvestments" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureFairValueMeasurements" roleURI="http://www.ardelyx.com/role/DisclosureFairValueMeasurements" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureDerivativeLiability" roleURI="http://www.ardelyx.com/role/DisclosureDerivativeLiability" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureBorrowing" roleURI="http://www.ardelyx.com/role/DisclosureBorrowing" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureLeases" roleURI="http://www.ardelyx.com/role/DisclosureLeases" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureEquityIncentivePlans" roleURI="http://www.ardelyx.com/role/DisclosureEquityIncentivePlans" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureNetLossPerShare" roleURI="http://www.ardelyx.com/role/DisclosureNetLossPerShare" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureCollaborationAndLicensingAgreements" roleURI="http://www.ardelyx.com/role/DisclosureCollaborationAndLicensingAgreements" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureContingencies" roleURI="http://www.ardelyx.com/role/DisclosureContingencies" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureIncomeTaxes" roleURI="http://www.ardelyx.com/role/DisclosureIncomeTaxes" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureOrganizationAndBasisOfPresentationPolicies" roleURI="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationPolicies" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureCashCashEquivalentsAndShortTermInvestmentsTables" roleURI="http://www.ardelyx.com/role/DisclosureCashCashEquivalentsAndShortTermInvestmentsTables" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureFairValueMeasurementsTables" roleURI="http://www.ardelyx.com/role/DisclosureFairValueMeasurementsTables" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureDerivativeLiabilityTables" roleURI="http://www.ardelyx.com/role/DisclosureDerivativeLiabilityTables" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureBorrowingTables" roleURI="http://www.ardelyx.com/role/DisclosureBorrowingTables" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureLeasesTables" roleURI="http://www.ardelyx.com/role/DisclosureLeasesTables" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureEquityIncentivePlansTables" roleURI="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansTables" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureNetLossPerShareTables" roleURI="http://www.ardelyx.com/role/DisclosureNetLossPerShareTables" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureCollaborationAndLicensingAgreementsTables" roleURI="http://www.ardelyx.com/role/DisclosureCollaborationAndLicensingAgreementsTables" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureOrganizationAndBasisOfPresentationAdditionalInformationDetails" roleURI="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationAdditionalInformationDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureOrganizationAndBasisOfPresentationPriorPeriodErrorsDetails" roleURI="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationPriorPeriodErrorsDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureOrganizationAndBasisOfPresentationCumulativeAdjustmentsDetails" roleURI="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationCumulativeAdjustmentsDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureOrganizationAndBasisOfPresentationLiquidityDetails" roleURI="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationLiquidityDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureCashCashEquivalentsAndShortTermInvestmentsScheduleOfSecuritiesClassifiedAsCashCashEquivalentsAndShortTermInvestmentsDetails" roleURI="http://www.ardelyx.com/role/DisclosureCashCashEquivalentsAndShortTermInvestmentsScheduleOfSecuritiesClassifiedAsCashCashEquivalentsAndShortTermInvestmentsDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureCashCashEquivalentsAndShortTermInvestmentsAdditionalInformationDetails" roleURI="http://www.ardelyx.com/role/DisclosureCashCashEquivalentsAndShortTermInvestmentsAdditionalInformationDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureFairValueMeasurementsSummaryOfFairValueMeasurementsOfCompanySFinancialAssetsAndLiabilitiesDetails" roleURI="http://www.ardelyx.com/role/DisclosureFairValueMeasurementsSummaryOfFairValueMeasurementsOfCompanySFinancialAssetsAndLiabilitiesDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureFairValueMeasurementsAdditionalInformationDetails" roleURI="http://www.ardelyx.com/role/DisclosureFairValueMeasurementsAdditionalInformationDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureDerivativeLiabilityAdditionalInformationDetails" roleURI="http://www.ardelyx.com/role/DisclosureDerivativeLiabilityAdditionalInformationDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureDerivativeLiabilityScheduleOfChangesInFairValueDetails" roleURI="http://www.ardelyx.com/role/DisclosureDerivativeLiabilityScheduleOfChangesInFairValueDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureBorrowingDetails" roleURI="http://www.ardelyx.com/role/DisclosureBorrowingDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureLeasesBalanceSheetAndStatementOfOperationsDetails" roleURI="http://www.ardelyx.com/role/DisclosureLeasesBalanceSheetAndStatementOfOperationsDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureLeasesUndiscountedCashPaymentObligationsDetails" roleURI="http://www.ardelyx.com/role/DisclosureLeasesUndiscountedCashPaymentObligationsDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureEquityIncentivePlansAdditionalInformationDetails" roleURI="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansAdditionalInformationDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureEquityIncentivePlansSummaryOfWeightedAverageAssumptionsToEstimateFairValueOfEmployeeStockOptionsDetails" roleURI="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansSummaryOfWeightedAverageAssumptionsToEstimateFairValueOfEmployeeStockOptionsDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureEquityIncentivePlansSummaryOfStockBasedCompensationExpenseRecognizedDetails" roleURI="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansSummaryOfStockBasedCompensationExpenseRecognizedDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureEquityIncentivePlansUnrecognizedStockBasedCompensationDetails" roleURI="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansUnrecognizedStockBasedCompensationDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureNetLossPerShareComputationOfBasicAndDilutedLossPerShareAttributableToCommonStockholdersDetails" roleURI="http://www.ardelyx.com/role/DisclosureNetLossPerShareComputationOfBasicAndDilutedLossPerShareAttributableToCommonStockholdersDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureNetLossPerShareAdditionalInformationDetails" roleURI="http://www.ardelyx.com/role/DisclosureNetLossPerShareAdditionalInformationDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureCollaborationAndLicensingAgreementsAdditionalInformationDetails" roleURI="http://www.ardelyx.com/role/DisclosureCollaborationAndLicensingAgreementsAdditionalInformationDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureCollaborationAndLicensingAgreementsScheduleOfChangesInDeferredRevenueDetails" roleURI="http://www.ardelyx.com/role/DisclosureCollaborationAndLicensingAgreementsScheduleOfChangesInDeferredRevenueDetails" />
  <roleRef xlink:type="simple" xlink:href="ardx-20200331.xsd#DisclosureContingenciesAdditionalInformationDetails" roleURI="http://www.ardelyx.com/role/DisclosureContingenciesAdditionalInformationDetails" />
  <presentationLink xlink:role="http://www.ardelyx.com/role/DocumentDocumentAndEntityInformation" xlink:type="extended" xlink:title="00090 - Document - Document and Entity Information">
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_CoverAbstract" xlink:label="dei_CoverAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentType" xlink:label="dei_DocumentType_637244601157176067" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_DocumentType_637244601157176067" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_DocumentPeriodEndDate_637244601157215960" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_EntityRegistrantName_637244601157215960" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_EntityCurrentReportingStatus_637244601157215960" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_EntityInteractiveDataCurrent_637244601157215960" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_EntityFilerCategory_637244601157215960" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_EntitySmallBusiness_637244601157215960" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_EntityEmergingGrowthCompany_637244601157215960" order="8" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_EntityShellCompany_637244601157215960" order="9" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_EntityCommonStockSharesOutstanding_637244601157215960" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_EntityCentralIndexKey_637244601157215960" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_CurrentFiscalYearEndDate_637244601157215960" order="12" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_DocumentFiscalYearFocus_637244601157215960" order="13" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_DocumentFiscalPeriodFocus_637244601157215960" order="14" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag_637244601157215960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_AmendmentFlag_637244601157215960" order="15" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/StatementCondensedBalanceSheets" xlink:type="extended" xlink:title="00100 - Statement - CONDENSED BALANCE SHEETS">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="StatementOfFinancialPositionAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AssetsAbstract_637244601157225932" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_637244601157225932" xlink:to="us-gaap_AssetsCurrentAbstract_637244601157225932" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract_637244601157225932" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_637244601157225932" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract_637244601157225932" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_637244601157225932" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerAssetNetCurrent" xlink:label="us-gaap_ContractWithCustomerAssetNetCurrent_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract_637244601157225932" xlink:to="us-gaap_ContractWithCustomerAssetNetCurrent_637244601157225932" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract_637244601157225932" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_637244601157225932" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract_637244601157225932" xlink:to="us-gaap_AssetsCurrent_637244601157225932" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_637244601157225932" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_637244601157225932" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_637244601157225932" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_637244601157225932" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_637244601157225932" xlink:to="us-gaap_OtherAssetsNoncurrent_637244601157225932" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_637244601157225932" xlink:to="us-gaap_Assets_637244601157225932" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_637244601157225932" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_637244601157225932" xlink:to="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" xlink:to="us-gaap_AccountsPayableCurrent_637244601157225932" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrent_637244601157225932" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_637244601157225932" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" xlink:to="us-gaap_ContractWithCustomerLiabilityCurrent_637244601157225932" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent_637244601157235922" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LoansPayableCurrent" xlink:label="us-gaap_LoansPayableCurrent_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" xlink:to="us-gaap_LoansPayableCurrent_637244601157235922" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredRevenue" xlink:label="us-gaap_DeferredRevenue_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" xlink:to="us-gaap_DeferredRevenue_637244601157235922" order="6" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccruedLiabilitiesAndOtherLiabilities" xlink:label="us-gaap_AccruedLiabilitiesAndOtherLiabilities_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" xlink:to="us-gaap_AccruedLiabilitiesAndOtherLiabilities_637244601157235922" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract_637244601157225932" xlink:to="us-gaap_LiabilitiesCurrent_637244601157235922" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_637244601157225932" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_637244601157235922" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermLoansPayable" xlink:label="us-gaap_LongTermLoansPayable_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_637244601157225932" xlink:to="us-gaap_LongTermLoansPayable_637244601157235922" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_637244601157225932" xlink:to="us-gaap_Liabilities_637244601157235922" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_637244601157225932" xlink:to="us-gaap_CommitmentsAndContingencies_637244601157235922" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_637244601157225932" xlink:to="us-gaap_StockholdersEquityAbstract_637244601157235922" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_637244601157235922" xlink:to="us-gaap_PreferredStockValue_637244601157235922" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_637244601157235922" xlink:to="us-gaap_CommonStockValue_637244601157235922" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_637244601157235922" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock_637244601157235922" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_637244601157235922" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_637244601157235922" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_637244601157235922" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_637244601157235922" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_637244601157245878" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_637244601157235922" xlink:to="us-gaap_StockholdersEquity_637244601157245878" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_637244601157225932" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_637244601157245878" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/StatementCondensedBalanceSheetsParenthetical" xlink:type="extended" xlink:title="00105 - Statement - CONDENSED BALANCE SHEETS (Parenthetical)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="StatementOfFinancialPositionAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare_637244601157245878" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesAuthorized_637244601157245878" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesIssued_637244601157245878" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesOutstanding_637244601157245878" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_637244601157245878" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesAuthorized_637244601157245878" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesIssued_637244601157245878" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding_637244601157245878" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesOutstanding_637244601157245878" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/StatementCondensedStatementsOfOperationsAndComprehensiveLoss" xlink:type="extended" xlink:title="00200 - Statement - CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="IncomeStatementAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="IncomeStatementAbstract" xlink:to="us-gaap_StatementTable_637244601157255851" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_637244601157255851" xlink:to="srt_ProductOrServiceAxis_637244601157255851" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductOrServiceAxis_637244601157255851" xlink:to="srt_ProductsAndServicesDomain_637244601157255851" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborativeDevelopmentMember" xlink:label="ardx_CollaborativeDevelopmentMember_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain_637244601157255851" xlink:to="ardx_CollaborativeDevelopmentMember_637244601157255851" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_OtherProductOrServicesRevenueMember" xlink:label="ardx_OtherProductOrServicesRevenueMember_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain_637244601157255851" xlink:to="ardx_OtherProductOrServicesRevenueMember_637244601157255851" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_637244601157255851" xlink:to="us-gaap_StatementLineItems_637244601157255851" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="us-gaap_RevenuesAbstract_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_RevenuesAbstract_637244601157255851" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenuesAbstract_637244601157255851" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_637244601157255851" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="us-gaap_OperatingExpensesAbstract_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_OperatingExpensesAbstract_637244601157255851" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract_637244601157255851" xlink:to="us-gaap_ResearchAndDevelopmentExpense_637244601157255851" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract_637244601157255851" xlink:to="us-gaap_GeneralAndAdministrativeExpense_637244601157255851" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract_637244601157255851" xlink:to="us-gaap_OperatingExpenses_637244601157255851" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_OperatingIncomeLoss_637244601157255851" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InterestExpense" xlink:label="us-gaap_InterestExpense_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_InterestExpense_637244601157255851" order="4" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="8" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense_637244601157255851" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_NonoperatingIncomeExpense_637244601157255851" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_637244601157275803" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_637244601157275803" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit_637244601157275803" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_IncomeTaxExpenseBenefit_637244601157275803" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_637244601157275803" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_NetIncomeLoss_637244601157275803" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted_637244601157275803" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_EarningsPerShareBasicAndDiluted_637244601157275803" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_637244601157275803" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_637244601157275803" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:label="us-gaap_ComprehensiveIncomeNetOfTaxAbstract_637244601157275803" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157255851" xlink:to="us-gaap_ComprehensiveIncomeNetOfTaxAbstract_637244601157275803" order="11" use="optional" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_6372446011572758031" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComprehensiveIncomeNetOfTaxAbstract_637244601157275803" xlink:to="us-gaap_NetIncomeLoss_6372446011572758031" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_637244601157275803" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComprehensiveIncomeNetOfTaxAbstract_637244601157275803" xlink:to="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_637244601157275803" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_637244601157275803" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComprehensiveIncomeNetOfTaxAbstract_637244601157275803" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax_637244601157275803" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="3" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/StatementCondensedStatementsOfChangesInStockholdersEquity" xlink:type="extended" xlink:title="00300 - Statement - CONDENSED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="StatementOfStockholdersEquityAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementTable_637244601157285774" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_637244601157285774" xlink:to="us-gaap_StatementEquityComponentsAxis_637244601157285774" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_637244601157285774" xlink:to="us-gaap_CommonStockMember_637244601157285774" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_637244601157285774" xlink:to="us-gaap_AdditionalPaidInCapitalMember_637244601157285774" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_637244601157285774" xlink:to="us-gaap_RetainedEarningsMember_637244601157285774" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_637244601157285774" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeMember_637244601157285774" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_637244601157285774" xlink:to="us-gaap_EquityComponentDomain_637244601157285774" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_637244601157285774" xlink:to="us-gaap_StatementLineItems_637244601157285774" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_StockholdersEquity_637244601157285774" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharesOutstanding" xlink:label="us-gaap_SharesOutstanding_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_SharesOutstanding_637244601157285774" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:label="us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_637244601157285774" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:label="us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_637244601157285774" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_637244601157285774" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_637244601157285774" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_637244601157285774" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_637244601157285774" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_637244601157285774" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_NetIncomeLoss_637244601157285774" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_6372446011572857741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_StockholdersEquity_6372446011572857741" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharesOutstanding" xlink:label="us-gaap_SharesOutstanding_6372446011572857741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_637244601157285774" xlink:to="us-gaap_SharesOutstanding_6372446011572857741" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/StatementCondensedStatementsOfCashFlows" xlink:type="extended" xlink:title="00400 - Statement - CONDENSED STATEMENTS OF CASH FLOWS">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="StatementOfCashFlowsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProfitLoss" xlink:label="us-gaap_ProfitLoss_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_ProfitLoss_637244601157295746" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Depreciation" xlink:label="us-gaap_Depreciation_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_Depreciation_637244601157295746" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AmortizationOfFinancingCosts" xlink:label="us-gaap_AmortizationOfFinancingCosts_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_AmortizationOfFinancingCosts_637244601157295746" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AmortizationOfDeferredCharges" xlink:label="us-gaap_AmortizationOfDeferredCharges_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_AmortizationOfDeferredCharges_637244601157295746" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_637244601157295746" order="4" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_NonCashLeaseExpense" xlink:label="ardx_NonCashLeaseExpense_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="ardx_NonCashLeaseExpense_637244601157295746" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_ShareBasedCompensation_637244601157295746" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInDerivativeLiabilities" xlink:label="us-gaap_IncreaseDecreaseInDerivativeLiabilities_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_IncreaseDecreaseInDerivativeLiabilities_637244601157295746" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_NoncashInterestExpense" xlink:label="ardx_NoncashInterestExpense_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="ardx_NoncashInterestExpense_637244601157295746" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_637244601157295746" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_IncreaseDecreaseInUnbilledRevenue" xlink:label="ardx_IncreaseDecreaseInUnbilledRevenue_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_637244601157295746" xlink:to="ardx_IncreaseDecreaseInUnbilledRevenue_637244601157295746" order="1" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_637244601157295746" xlink:to="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_637244601157295746" order="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_637244601157295746" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable_637244601157295746" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_637244601157295746" xlink:to="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_637244601157295746" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_IncreaseDecreaseInOperatingLeaseLiabilities" xlink:label="ardx_IncreaseDecreaseInOperatingLeaseLiabilities_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_637244601157295746" xlink:to="ardx_IncreaseDecreaseInOperatingLeaseLiabilities_637244601157295746" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_637244601157295746" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities_637244601157295746" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_637244601157295746" xlink:to="us-gaap_IncreaseDecreaseInDeferredRevenue_637244601157295746" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_637244601157295746" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_637244601157295746" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_637244601157295746" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities" xlink:label="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_637244601157305718" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquireShortTermInvestments" xlink:label="us-gaap_PaymentsToAcquireShortTermInvestments_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_PaymentsToAcquireShortTermInvestments_637244601157305718" order="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_637244601157305718" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_637244601157295746" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_637244601157305718" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_637244601157305718" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ProceedsFromIssuanceOfCommonStockUnderStockPlans" xlink:label="ardx_ProceedsFromIssuanceOfCommonStockUnderStockPlans_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_637244601157305718" xlink:to="ardx_ProceedsFromIssuanceOfCommonStockUnderStockPlans_637244601157305718" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_637244601157305718" xlink:to="us-gaap_ProceedsFromStockOptionsExercised_637244601157305718" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_637244601157305718" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_637244601157305718" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_637244601157305718" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_637244601157305718" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_6372446011573057181" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_6372446011573057181" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfCashFlowsAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract_637244601157305718" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxesPaidNet" xlink:label="us-gaap_IncomeTaxesPaidNet_637244601157305718" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract_637244601157305718" xlink:to="us-gaap_IncomeTaxesPaidNet_637244601157305718" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:label="us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_637244601157315692" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_637244601157315692" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_637244601157315692" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_637244601157315692" xlink:to="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_637244601157315692" order="1" use="optional" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentation" xlink:type="extended" xlink:title="10101 - Disclosure - Organization and Basis of Presentation">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock" xlink:label="us-gaap_OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock_637244601157315692" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="us-gaap_OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock_637244601157315692" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureCashCashEquivalentsAndShortTermInvestments" xlink:type="extended" xlink:title="10201 - Disclosure - Cash, Cash Equivalents and Short-Term Investments">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAbstract" xlink:label="CashAndCashEquivalentsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashCashEquivalentsAndShortTermInvestmentsTextBlock" xlink:label="us-gaap_CashCashEquivalentsAndShortTermInvestmentsTextBlock_637244601157315692" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CashAndCashEquivalentsAbstract" xlink:to="us-gaap_CashCashEquivalentsAndShortTermInvestmentsTextBlock_637244601157315692" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureFairValueMeasurements" xlink:type="extended" xlink:title="10301 - Disclosure - Fair Value Measurements">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:label="us-gaap_FairValueDisclosuresTextBlock_637244601157315692" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueDisclosuresTextBlock_637244601157315692" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureDerivativeLiability" xlink:type="extended" xlink:title="10401 - Disclosure - Derivative Liability">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock_637244601157315692" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock_637244601157315692" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="8" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureBorrowing" xlink:type="extended" xlink:title="10501 - Disclosure - Borrowing">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtDisclosureTextBlock" xlink:label="us-gaap_DebtDisclosureTextBlock_637244601157315692" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_DebtDisclosureTextBlock_637244601157315692" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureLeases" xlink:type="extended" xlink:title="10601 - Disclosure - Leases">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeasesAbstract" xlink:label="us-gaap_LeasesAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeasesTextBlock" xlink:label="us-gaap_LesseeOperatingLeasesTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_LesseeOperatingLeasesTextBlock_637244601157325667" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureEquityIncentivePlans" xlink:type="extended" xlink:title="10701 - Disclosure - Equity Incentive Plans">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_636737256074065195" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_636737256074065195" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_637244601157325667" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureNetLossPerShare" xlink:type="extended" xlink:title="10801 - Disclosure - Net Loss Per Share">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="EarningsPerShareAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="us-gaap_EarningsPerShareTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareTextBlock_637244601157325667" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureCollaborationAndLicensingAgreements" xlink:type="extended" xlink:title="10901 - Disclosure - Collaboration and Licensing Agreements">
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsAbstract" xlink:label="ardx_CollaborationAndLicensingAgreementsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CollaborativeArrangementDisclosureTextBlock" xlink:label="us-gaap_CollaborativeArrangementDisclosureTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CollaborationAndLicensingAgreementsAbstract" xlink:to="us-gaap_CollaborativeArrangementDisclosureTextBlock_637244601157325667" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureContingencies" xlink:type="extended" xlink:title="11001 - Disclosure - Contingencies">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="CommitmentsAndContingenciesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_637244601157325667" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="8" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureIncomeTaxes" xlink:type="extended" xlink:title="11101 - Disclosure - Income Taxes">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="IncomeTaxDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock_637244601157325667" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationPolicies" xlink:type="extended" xlink:title="20102 - Disclosure - Organization and Basis of Presentation (Policies)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="AccountingPoliciesAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="AccountingPoliciesAbstract" xlink:to="us-gaap_BasisOfAccountingPolicyPolicyTextBlock_637244601157325667" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_PriorPeriodErrorsPolicyTextBlock" xlink:label="ardx_PriorPeriodErrorsPolicyTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="AccountingPoliciesAbstract" xlink:to="ardx_PriorPeriodErrorsPolicyTextBlock_637244601157325667" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_LiquidityPolicyTextBlock" xlink:label="ardx_LiquidityPolicyTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="AccountingPoliciesAbstract" xlink:to="ardx_LiquidityPolicyTextBlock_637244601157325667" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="AccountingPoliciesAbstract" xlink:to="us-gaap_UseOfEstimates_637244601157325667" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="AccountingPoliciesAbstract" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_637244601157325667" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock_637244601157325667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="AccountingPoliciesAbstract" xlink:to="us-gaap_FairValueMeasurementPolicyPolicyTextBlock_637244601157325667" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureCashCashEquivalentsAndShortTermInvestmentsTables" xlink:type="extended" xlink:title="30203 - Disclosure - Cash, Cash Equivalents and Short-Term Investments (Tables)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAbstract" xlink:label="CashAndCashEquivalentsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock" xlink:label="us-gaap_ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock_637244601157335639" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CashAndCashEquivalentsAbstract" xlink:to="us-gaap_ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock_637244601157335639" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureFairValueMeasurementsTables" xlink:type="extended" xlink:title="30303 - Disclosure - Fair Value Measurements (Tables)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_637244601157335639" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueDisclosuresAbstract" xlink:to="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_637244601157335639" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureDerivativeLiabilityTables" xlink:type="extended" xlink:title="30403 - Disclosure - Derivative Liability (Tables)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ScheduleOfChangesInFairValueTableTextBlock" xlink:label="ardx_ScheduleOfChangesInFairValueTableTextBlock_637244601157335639" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="ardx_ScheduleOfChangesInFairValueTableTextBlock_637244601157335639" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureBorrowingTables" xlink:type="extended" xlink:title="30503 - Disclosure - Borrowing (Tables)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract_636737256074075222" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_637244601157335639" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtDisclosureAbstract_636737256074075222" xlink:to="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_637244601157335639" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureLeasesTables" xlink:type="extended" xlink:title="30603 - Disclosure - Leases (Tables)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeasesAbstract" xlink:label="us-gaap_LeasesAbstract" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ScheduleOfAdditionalDetailsOfLeasesTableTextBlock" xlink:label="ardx_ScheduleOfAdditionalDetailsOfLeasesTableTextBlock_637244601157335639" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="ardx_ScheduleOfAdditionalDetailsOfLeasesTableTextBlock_637244601157335639" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeaseCostTableTextBlock" xlink:label="us-gaap_LeaseCostTableTextBlock_637244601157335639" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_LeaseCostTableTextBlock_637244601157335639" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_637244601157335639" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_637244601157335639" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansTables" xlink:type="extended" xlink:title="30703 - Disclosure - Equity Incentive Plans (Tables)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_637244601157345612" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_637244601157345612" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock" xlink:label="us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock_637244601157345612" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureNetLossPerShareTables" xlink:type="extended" xlink:title="30803 - Disclosure - Net Loss Per Share (Tables)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="EarningsPerShareAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="EarningsPerShareAbstract" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_637244601157345612" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureCollaborationAndLicensingAgreementsTables" xlink:type="extended" xlink:title="30903 - Disclosure - Collaboration and Licensing Agreements (Tables)">
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsAbstract" xlink:label="ardx_CollaborationAndLicensingAgreementsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:label="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CollaborationAndLicensingAgreementsAbstract" xlink:to="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_637244601157345612" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationAdditionalInformationDetails" xlink:type="extended" xlink:title="40101 - Disclosure - Organization and Basis of Presentation - Additional Information (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="us-gaap_NumberOfOperatingSegments_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="us-gaap_NumberOfOperatingSegments_637244601157345612" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationPriorPeriodErrorsDetails" xlink:type="extended" xlink:title="40102 - Disclosure - Organization and Basis of Presentation - Prior Period Errors (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable" xlink:label="us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable_637244601157345612" order="1" use="optional" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis" xlink:label="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable_637244601157345612" xlink:to="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis_637244601157345612" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdjustmentsForErrorCorrectionDomain" xlink:label="us-gaap_AdjustmentsForErrorCorrectionDomain_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis_637244601157345612" xlink:to="us-gaap_AdjustmentsForErrorCorrectionDomain_637244601157345612" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_OverstatementDueToClinicalTrialAccrualsErrorsMember" xlink:label="ardx_OverstatementDueToClinicalTrialAccrualsErrorsMember_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsForErrorCorrectionDomain_637244601157345612" xlink:to="ardx_OverstatementDueToClinicalTrialAccrualsErrorsMember_637244601157345612" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RestatementAxis" xlink:label="srt_RestatementAxis_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable_637244601157345612" xlink:to="srt_RestatementAxis_637244601157345612" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RestatementDomain" xlink:label="srt_RestatementDomain_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RestatementAxis_637244601157345612" xlink:to="srt_RestatementDomain_637244601157345612" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RestatementAdjustmentMember" xlink:label="srt_RestatementAdjustmentMember_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RestatementDomain_637244601157345612" xlink:to="srt_RestatementAdjustmentMember_637244601157345612" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems" xlink:label="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable_637244601157345612" xlink:to="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems_637244601157345612" order="3" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems_637244601157345612" xlink:to="us-gaap_ResearchAndDevelopmentExpense_637244601157345612" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccruedLiabilitiesAndOtherLiabilities" xlink:label="us-gaap_AccruedLiabilitiesAndOtherLiabilities_637244601157345612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems_637244601157345612" xlink:to="us-gaap_AccruedLiabilitiesAndOtherLiabilities_637244601157345612" order="2" use="optional" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationCumulativeAdjustmentsDetails" xlink:type="extended" xlink:title="40103 - Disclosure - Organization and Basis of Presentation - Cumulative adjustments (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfQuantifyingPriorYearMisstatementCorrectedInCurrentYearFinancialStatementsTable" xlink:label="us-gaap_ScheduleOfQuantifyingPriorYearMisstatementCorrectedInCurrentYearFinancialStatementsTable_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ScheduleOfQuantifyingPriorYearMisstatementCorrectedInCurrentYearFinancialStatementsTable_637244601157355587" order="1" use="optional" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis" xlink:label="us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfQuantifyingPriorYearMisstatementCorrectedInCurrentYearFinancialStatementsTable_637244601157355587" xlink:to="us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_637244601157355587" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NatureOfErrorDomain" xlink:label="us-gaap_NatureOfErrorDomain_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_637244601157355587" xlink:to="us-gaap_NatureOfErrorDomain_637244601157355587" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ReductionInAccruedAndOtherLiabilitiesMember" xlink:label="ardx_ReductionInAccruedAndOtherLiabilitiesMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NatureOfErrorDomain_637244601157355587" xlink:to="ardx_ReductionInAccruedAndOtherLiabilitiesMember_637244601157355587" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ReductionInResearchAndDevelopmentExpensesMember" xlink:label="ardx_ReductionInResearchAndDevelopmentExpensesMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NatureOfErrorDomain_637244601157355587" xlink:to="ardx_ReductionInResearchAndDevelopmentExpensesMember_637244601157355587" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsLineItems" xlink:label="us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsLineItems_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfQuantifyingPriorYearMisstatementCorrectedInCurrentYearFinancialStatementsTable_637244601157355587" xlink:to="us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsLineItems_637244601157355587" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount" xlink:label="us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsLineItems_637244601157355587" xlink:to="us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount_637244601157355587" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureOrganizationAndBasisOfPresentationLiquidityDetails" xlink:type="extended" xlink:title="40104 - Disclosure - Organization and Basis of Presentation - Liquidity (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashCashEquivalentsAndShortTermInvestments" xlink:label="us-gaap_CashCashEquivalentsAndShortTermInvestments_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="us-gaap_CashCashEquivalentsAndShortTermInvestments_637244601157355587" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureCashCashEquivalentsAndShortTermInvestmentsScheduleOfSecuritiesClassifiedAsCashCashEquivalentsAndShortTermInvestmentsDetails" xlink:type="extended" xlink:title="40201 - Disclosure - Cash, Cash Equivalents and Short-Term Investments - Schedule of Securities Classified as Cash, Cash Equivalents and Short-term Investments (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAbstract" xlink:label="CashAndCashEquivalentsAbstract" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CashCashEquivalentsAndShortTermInvestmentsTable" xlink:label="ardx_CashCashEquivalentsAndShortTermInvestmentsTable_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CashAndCashEquivalentsAbstract" xlink:to="ardx_CashCashEquivalentsAndShortTermInvestmentsTable_637244601157355587" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsTable_637244601157355587" xlink:to="us-gaap_FinancialInstrumentAxis_637244601157355587" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis_637244601157355587" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_637244601157355587" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember" xlink:label="us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_637244601157355587" xlink:to="us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember_637244601157355587" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="us-gaap_CorporateDebtSecuritiesMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_637244601157355587" xlink:to="us-gaap_CorporateDebtSecuritiesMember_637244601157355587" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetBackedSecuritiesMember" xlink:label="us-gaap_AssetBackedSecuritiesMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_637244601157355587" xlink:to="us-gaap_AssetBackedSecuritiesMember_637244601157355587" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_USTreasuryNotesSecuritiesMember" xlink:label="us-gaap_USTreasuryNotesSecuritiesMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_637244601157355587" xlink:to="us-gaap_USTreasuryNotesSecuritiesMember_637244601157355587" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAxis" xlink:label="us-gaap_CashAndCashEquivalentsAxis_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsTable_637244601157355587" xlink:to="us-gaap_CashAndCashEquivalentsAxis_637244601157355587" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAxis_637244601157355587" xlink:to="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_637244601157355587" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MoneyMarketFundsMember" xlink:label="us-gaap_MoneyMarketFundsMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_637244601157355587" xlink:to="us-gaap_MoneyMarketFundsMember_637244601157355587" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommercialPaperMember" xlink:label="us-gaap_CommercialPaperMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_637244601157355587" xlink:to="us-gaap_CommercialPaperMember_637244601157355587" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="us-gaap_CorporateDebtSecuritiesMember_6372446011573555871" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_637244601157355587" xlink:to="us-gaap_CorporateDebtSecuritiesMember_6372446011573555871" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashMember" xlink:label="us-gaap_CashMember_637244601157355587" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_637244601157355587" xlink:to="us-gaap_CashMember_637244601157355587" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems" xlink:label="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsTable_637244601157355587" xlink:to="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" order="3" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_637244601157365559" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCashEquivalentsAtCarryingValue" xlink:label="us-gaap_OtherCashEquivalentsAtCarryingValue_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="us-gaap_OtherCashEquivalentsAtCarryingValue_637244601157365559" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="8" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CashAndCashEquivalentsGrossUnrealizedGains" xlink:label="ardx_CashAndCashEquivalentsGrossUnrealizedGains_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="ardx_CashAndCashEquivalentsGrossUnrealizedGains_637244601157365559" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="us-gaap_CashAndCashEquivalentsFairValueDisclosure_637244601157365559" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_637244601157365559" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_637244601157365559" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_637244601157365559" order="7" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecurities_637244601157365559" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashCashEquivalentsAndShortTermInvestments" xlink:label="us-gaap_CashCashEquivalentsAndShortTermInvestments_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="us-gaap_CashCashEquivalentsAndShortTermInvestments_637244601157365559" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CashCashEquivalentsAndShortTermInvestmentsGrossUnrealizedGains" xlink:label="ardx_CashCashEquivalentsAndShortTermInvestmentsGrossUnrealizedGains_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="ardx_CashCashEquivalentsAndShortTermInvestmentsGrossUnrealizedGains_637244601157365559" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CashCashEquivalentsAndShortTermInvestmentsGrossUnrealizedLosses" xlink:label="ardx_CashCashEquivalentsAndShortTermInvestmentsGrossUnrealizedLosses_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="ardx_CashCashEquivalentsAndShortTermInvestmentsGrossUnrealizedLosses_637244601157365559" order="11" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CashCashEquivalentsAndShortTermInvestmentsFairValueDisclosure" xlink:label="ardx_CashCashEquivalentsAndShortTermInvestmentsFairValueDisclosure_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157365559" xlink:to="ardx_CashCashEquivalentsAndShortTermInvestmentsFairValueDisclosure_637244601157365559" order="12" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureCashCashEquivalentsAndShortTermInvestmentsAdditionalInformationDetails" xlink:type="extended" xlink:title="40202 - Disclosure - Cash, Cash Equivalents and Short-Term Investments - Additional Information (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAbstract" xlink:label="CashAndCashEquivalentsAbstract" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CashCashEquivalentsAndShortTermInvestmentsTable" xlink:label="ardx_CashCashEquivalentsAndShortTermInvestmentsTable_637244601157365559" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CashAndCashEquivalentsAbstract" xlink:to="ardx_CashCashEquivalentsAndShortTermInvestmentsTable_637244601157365559" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsTable_637244601157365559" xlink:to="srt_RangeAxis_637244601157375531" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="srt_RangeMember_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis_637244601157375531" xlink:to="srt_RangeMember_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_637244601157375531" xlink:to="srt_MaximumMember_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems" xlink:label="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsTable_637244601157365559" xlink:to="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157375531" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157375531" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherThanTemporaryImpairmentLossDebtSecuritiesAvailableForSale" xlink:label="us-gaap_OtherThanTemporaryImpairmentLossDebtSecuritiesAvailableForSale_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157375531" xlink:to="us-gaap_OtherThanTemporaryImpairmentLossDebtSecuritiesAvailableForSale_637244601157375531" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_AvailableForSaleSecuritiesContractualMaturityPeriod" xlink:label="ardx_AvailableForSaleSecuritiesContractualMaturityPeriod_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CashCashEquivalentsAndShortTermInvestmentsLineItems_637244601157375531" xlink:to="ardx_AvailableForSaleSecuritiesContractualMaturityPeriod_637244601157375531" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureFairValueMeasurementsSummaryOfFairValueMeasurementsOfCompanySFinancialAssetsAndLiabilitiesDetails" xlink:type="extended" xlink:title="40301 - Disclosure - Fair Value Measurements - Summary of Fair Value Measurements of Company's Financial Assets and Liabilities (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_637244601157375531" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="us-gaap_FairValueByAssetClassAxis_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_637244601157375531" xlink:to="us-gaap_FairValueByAssetClassAxis_637244601157375531" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByAssetClassAxis_637244601157375531" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MoneyMarketFundsMember" xlink:label="us-gaap_MoneyMarketFundsMember_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_637244601157375531" xlink:to="us-gaap_MoneyMarketFundsMember_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CommercialPaperCashEquivalentsIncludingSecuritiesMember" xlink:label="ardx_CommercialPaperCashEquivalentsIncludingSecuritiesMember_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_637244601157375531" xlink:to="ardx_CommercialPaperCashEquivalentsIncludingSecuritiesMember_637244601157375531" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_DomesticCorporateDebtSecuritiesIncludingCashEquivalentsMember" xlink:label="ardx_DomesticCorporateDebtSecuritiesIncludingCashEquivalentsMember_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_637244601157375531" xlink:to="ardx_DomesticCorporateDebtSecuritiesIncludingCashEquivalentsMember_637244601157375531" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetBackedSecuritiesMember" xlink:label="us-gaap_AssetBackedSecuritiesMember_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_637244601157375531" xlink:to="us-gaap_AssetBackedSecuritiesMember_637244601157375531" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_USTreasuryNotesSecuritiesMember" xlink:label="us-gaap_USTreasuryNotesSecuritiesMember_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_637244601157375531" xlink:to="us-gaap_USTreasuryNotesSecuritiesMember_637244601157375531" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:label="us-gaap_FairValueByLiabilityClassAxis_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_637244601157375531" xlink:to="us-gaap_FairValueByLiabilityClassAxis_637244601157375531" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByLiabilityClassAxis_637244601157375531" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_DerivativeLiabilityExitFeeMember" xlink:label="ardx_DerivativeLiabilityExitFeeMember_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_637244601157375531" xlink:to="ardx_DerivativeLiabilityExitFeeMember_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_637244601157375531" xlink:to="us-gaap_FairValueByMeasurementFrequencyAxis_637244601157375531" order="3" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByMeasurementFrequencyAxis_637244601157375531" xlink:to="us-gaap_FairValueMeasurementFrequencyDomain_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="us-gaap_FairValueMeasurementsRecurringMember_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementFrequencyDomain_637244601157375531" xlink:to="us-gaap_FairValueMeasurementsRecurringMember_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_637244601157375531" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_637244601157375531" order="4" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_637244601157375531" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member_637244601157375531" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_637244601157375531" xlink:to="us-gaap_FairValueInputsLevel1Member_637244601157375531" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="us-gaap_FairValueInputsLevel2Member_637244601157385506" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_637244601157375531" xlink:to="us-gaap_FairValueInputsLevel2Member_637244601157385506" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member_637244601157385506" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_637244601157375531" xlink:to="us-gaap_FairValueInputsLevel3Member_637244601157385506" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_637244601157385506" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_637244601157375531" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_637244601157385506" order="5" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="us-gaap_AssetsFairValueDisclosureAbstract_637244601157385506" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_637244601157385506" xlink:to="us-gaap_AssetsFairValueDisclosureAbstract_637244601157385506" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="us-gaap_AssetsFairValueDisclosure_637244601157385506" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsFairValueDisclosureAbstract_637244601157385506" xlink:to="us-gaap_AssetsFairValueDisclosure_637244601157385506" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract" xlink:label="us-gaap_LiabilitiesFairValueDisclosureAbstract_637244601157385506" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_637244601157385506" xlink:to="us-gaap_LiabilitiesFairValueDisclosureAbstract_637244601157385506" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_637244601157385506" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesFairValueDisclosureAbstract_637244601157385506" xlink:to="us-gaap_LiabilitiesFairValueDisclosure_637244601157385506" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureFairValueMeasurementsAdditionalInformationDetails" xlink:type="extended" xlink:title="40302 - Disclosure - Fair Value Measurements - Additional Information (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount" xlink:label="us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount_637244601157395484" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount" xlink:label="us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount_637244601157395484" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureDerivativeLiabilityAdditionalInformationDetails" xlink:type="extended" xlink:title="40401 - Disclosure - Derivative Liability - Additional Information (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract_636737256074426150" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeTable" xlink:label="us-gaap_DerivativeTable_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract_636737256074426150" xlink:to="us-gaap_DerivativeTable_637244601157395484" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeTable_637244601157395484" xlink:to="us-gaap_DebtInstrumentAxis_637244601157395484" order="1" use="optional" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentAxis_637244601157395484" xlink:to="us-gaap_DebtInstrumentNameDomain_637244601157395484" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_SolarCapitalAndWesternAllianceBankLoanAgreementMember" xlink:label="ardx_SolarCapitalAndWesternAllianceBankLoanAgreementMember_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain_637244601157395484" xlink:to="ardx_SolarCapitalAndWesternAllianceBankLoanAgreementMember_637244601157395484" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeTable_637244601157395484" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_637244601157395484" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_637244601157395484" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_637244601157395484" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_637244601157395484" xlink:to="us-gaap_FairValueInputsLevel3Member_637244601157395484" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="us-gaap_DerivativeLineItems_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeTable_637244601157395484" xlink:to="us-gaap_DerivativeLineItems_637244601157395484" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessExitCosts1" xlink:label="us-gaap_BusinessExitCosts1_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_637244601157395484" xlink:to="us-gaap_BusinessExitCosts1_637244601157395484" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_PercentageOfReasonablyPossibleIncreaseInRiskAssumption" xlink:label="ardx_PercentageOfReasonablyPossibleIncreaseInRiskAssumption_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_637244601157395484" xlink:to="ardx_PercentageOfReasonablyPossibleIncreaseInRiskAssumption_637244601157395484" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_PercentageOfReasonablyPossibleDecreaseInRiskAssumption" xlink:label="ardx_PercentageOfReasonablyPossibleDecreaseInRiskAssumption_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_637244601157395484" xlink:to="ardx_PercentageOfReasonablyPossibleDecreaseInRiskAssumption_637244601157395484" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleIncreaseInDesignatedRiskComponent" xlink:label="ardx_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleIncreaseInDesignatedRiskComponent_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_637244601157395484" xlink:to="ardx_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleIncreaseInDesignatedRiskComponent_637244601157395484" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleDecreaseInDesignatedRiskComponent" xlink:label="ardx_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleDecreaseInDesignatedRiskComponent_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_637244601157395484" xlink:to="ardx_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleDecreaseInDesignatedRiskComponent_637244601157395484" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureDerivativeLiabilityScheduleOfChangesInFairValueDetails" xlink:type="extended" xlink:title="40402 - Disclosure - Derivative Liability - Schedule of Changes in Fair Value (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability" xlink:label="us-gaap_DerivativeFairValueOfDerivativeLiability_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_DerivativeFairValueOfDerivativeLiability_637244601157395484" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnrealizedGainLossOnDerivatives" xlink:label="us-gaap_UnrealizedGainLossOnDerivatives_637244601157395484" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_UnrealizedGainLossOnDerivatives_637244601157395484" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability" xlink:label="us-gaap_DerivativeFairValueOfDerivativeLiability_6372446011573954841" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_DerivativeFairValueOfDerivativeLiability_6372446011573954841" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" priority="3" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureBorrowingDetails" xlink:type="extended" xlink:title="40501 - Disclosure - Borrowing (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract_636737256074436181" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtDisclosureAbstract_636737256074436181" xlink:to="us-gaap_DebtInstrumentTable_637244601157405452" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="us-gaap_VariableRateAxis_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_637244601157405452" xlink:to="us-gaap_VariableRateAxis_637244601157405452" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="us-gaap_VariableRateDomain_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_VariableRateAxis_637244601157405452" xlink:to="us-gaap_VariableRateDomain_637244601157405452" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="us-gaap_LondonInterbankOfferedRateLIBORMember_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_VariableRateDomain_637244601157405452" xlink:to="us-gaap_LondonInterbankOfferedRateLIBORMember_637244601157405452" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodAxis_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_637244601157405452" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodAxis_637244601157405452" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodDomain_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodAxis_637244601157405452" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodDomain_637244601157405452" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_AtMaturityMember" xlink:label="ardx_AtMaturityMember_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodDomain_637244601157405452" xlink:to="ardx_AtMaturityMember_637244601157405452" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodOneMember" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodOneMember_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodDomain_637244601157405452" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodOneMember_637244601157405452" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodTwoMember" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodTwoMember_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodDomain_637244601157405452" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodTwoMember_637244601157405452" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_AfterSecondAnniversaryToMaturityDateMember" xlink:label="ardx_AfterSecondAnniversaryToMaturityDateMember_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodDomain_637244601157405452" xlink:to="ardx_AfterSecondAnniversaryToMaturityDateMember_637244601157405452" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_637244601157405452" xlink:to="us-gaap_DebtInstrumentLineItems_637244601157405452" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_637244601157405452" xlink:to="us-gaap_DebtInstrumentCarryingAmount_637244601157405452" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_637244601157405452" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_637244601157405452" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentDescriptionOfVariableRateBasis" xlink:label="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_637244601157405452" xlink:to="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_637244601157405452" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentPrincipal_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_637244601157405452" xlink:to="us-gaap_DebtInstrumentPeriodicPaymentPrincipal_637244601157405452" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_PercentageOfPremiumPayableOnRedemptionOfTermLoan" xlink:label="ardx_PercentageOfPremiumPayableOnRedemptionOfTermLoan_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_637244601157405452" xlink:to="ardx_PercentageOfPremiumPayableOnRedemptionOfTermLoan_637244601157405452" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_FeePayableUponClosingOfTermLoan" xlink:label="ardx_FeePayableUponClosingOfTermLoan_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_637244601157405452" xlink:to="ardx_FeePayableUponClosingOfTermLoan_637244601157405452" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_PrepaymentFeePercentage" xlink:label="ardx_PrepaymentFeePercentage_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_637244601157405452" xlink:to="ardx_PrepaymentFeePercentage_637244601157405452" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_DefaultInterestRate" xlink:label="ardx_DefaultInterestRate_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_637244601157405452" xlink:to="ardx_DefaultInterestRate_637244601157405452" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtByMaturityAbstract" xlink:label="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_637244601157405452" xlink:to="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_637244601157405452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_637244601157405452" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_637244601157415426" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_637244601157415426" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" xlink:to="us-gaap_DebtInstrumentCarryingAmount_637244601157415426" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_637244601157415426" order="5" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_DebtInstrumentUnaccretedValueFinalFee" xlink:label="ardx_DebtInstrumentUnaccretedValueFinalFee_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" xlink:to="ardx_DebtInstrumentUnaccretedValueFinalFee_637244601157415426" order="6" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebt" xlink:label="us-gaap_LongTermDebt_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" xlink:to="us-gaap_LongTermDebt_637244601157415426" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LoansPayableCurrent" xlink:label="us-gaap_LoansPayableCurrent_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" xlink:to="us-gaap_LoansPayableCurrent_637244601157415426" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermLoansPayable" xlink:label="us-gaap_LongTermLoansPayable_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongTermDebtByMaturityAbstract_637244601157405452" xlink:to="us-gaap_LongTermLoansPayable_637244601157415426" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="7" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureLeasesBalanceSheetAndStatementOfOperationsDetails" xlink:type="extended" xlink:title="40601 - Disclosure - Leases - Balance Sheet and Statement of Operations (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeasesAbstract" xlink:label="us-gaap_LeasesAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsAndLiabilitiesLesseeAbstract" xlink:label="us-gaap_AssetsAndLiabilitiesLesseeAbstract_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_AssetsAndLiabilitiesLesseeAbstract_637244601157415426" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAndLiabilitiesLesseeAbstract_637244601157415426" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_637244601157415426" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAndLiabilitiesLesseeAbstract_637244601157415426" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent_637244601157415426" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAndLiabilitiesLesseeAbstract_637244601157415426" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_637244601157415426" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability_637244601157415426" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAndLiabilitiesLesseeAbstract_637244601157415426" xlink:to="us-gaap_OperatingLeaseLiability_637244601157415426" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAndLiabilitiesLesseeAbstract_637244601157415426" xlink:to="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_637244601157425399" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAndLiabilitiesLesseeAbstract_637244601157415426" xlink:to="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_637244601157425399" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeaseCostAbstract" xlink:label="us-gaap_LeaseCostAbstract_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_LeaseCostAbstract_637244601157425399" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseCost" xlink:label="us-gaap_OperatingLeaseCost_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract_637244601157425399" xlink:to="us-gaap_OperatingLeaseCost_637244601157425399" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeasePayments" xlink:label="us-gaap_OperatingLeasePayments_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract_637244601157425399" xlink:to="us-gaap_OperatingLeasePayments_637244601157425399" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureLeasesUndiscountedCashPaymentObligationsDetails" xlink:type="extended" xlink:title="40602 - Disclosure - Leases - Undiscounted Cash Payment Obligations (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeasesAbstract" xlink:label="us-gaap_LeasesAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_637244601157425399" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_637244601157425399" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_637244601157425399" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_637244601157425399" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_637244601157425399" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_637244601157425399" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_637244601157425399" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_637244601157425399" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_637244601157425399" order="4" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="9" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_637244601157425399" xlink:to="us-gaap_OperatingLeaseLiability_637244601157425399" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_637244601157425399" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent_637244601157425399" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="9" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_637244601157425399" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_637244601157425399" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="8" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansAdditionalInformationDetails" xlink:type="extended" xlink:title="40701 - Disclosure - Equity Incentive Plans - Additional Information (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_636737256074536433" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_636737256074536433" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157425399" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157425399" xlink:to="us-gaap_AwardTypeAxis_637244601157425399" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis_637244601157425399" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_637244601157425399" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="us-gaap_EmployeeStockOptionMember_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_637244601157425399" xlink:to="us-gaap_EmployeeStockOptionMember_637244601157425399" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_637244601157425399" xlink:to="us-gaap_RestrictedStockUnitsRSUMember_637244601157425399" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_PerformanceBasedRestrictedStockUnitsMember" xlink:label="ardx_PerformanceBasedRestrictedStockUnitsMember_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_637244601157425399" xlink:to="ardx_PerformanceBasedRestrictedStockUnitsMember_637244601157425399" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157425399" xlink:to="us-gaap_PlanNameAxis_637244601157425399" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="us-gaap_PlanNameDomain_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameAxis_637244601157425399" xlink:to="us-gaap_PlanNameDomain_637244601157425399" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_EmployeeStockPurchasePlanMember" xlink:label="ardx_EmployeeStockPurchasePlanMember_637244601157425399" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain_637244601157425399" xlink:to="ardx_EmployeeStockPurchasePlanMember_637244601157425399" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157425399" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" order="3" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_637244601157435372" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_637244601157435372" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_637244601157435372" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_ProceedsFromStockOptionsExercised_637244601157435372" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_637244601157435372" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_637244601157435372" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_637244601157435372" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_637244601157435372" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:label="us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_637244601157435372" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_SharePrice_637244601157435372" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:label="us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157435372" xlink:to="us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_637244601157435372" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="6" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansSummaryOfWeightedAverageAssumptionsToEstimateFairValueOfEmployeeStockOptionsDetails" xlink:type="extended" xlink:title="40702 - Disclosure - Equity Incentive Plans - Summary of Weighted-Average Assumptions to Estimate Fair value of Employee Stock Options (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_637244601157435372" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_637244601157435372" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_637244601157435372" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_637244601157435372" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansSummaryOfStockBasedCompensationExpenseRecognizedDetails" xlink:type="extended" xlink:title="40703 - Disclosure - Equity Incentive Plans - Summary of Stock-Based Compensation Expense Recognized (Details)">
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosuresAbstract" xlink:label="ardx_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosuresAbstract_636737256074526402" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosuresAbstract_636737256074526402" xlink:to="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_637244601157445345" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="us-gaap_IncomeStatementLocationAxis_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_637244601157445345" xlink:to="us-gaap_IncomeStatementLocationAxis_637244601157445345" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="us-gaap_IncomeStatementLocationDomain_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementLocationAxis_637244601157445345" xlink:to="us-gaap_IncomeStatementLocationDomain_637244601157445345" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementLocationDomain_637244601157445345" xlink:to="us-gaap_ResearchAndDevelopmentExpenseMember_637244601157445345" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementLocationDomain_637244601157445345" xlink:to="us-gaap_GeneralAndAdministrativeExpenseMember_637244601157445345" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_637244601157445345" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_637244601157445345" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_637244601157445345" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_637244601157445345" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureEquityIncentivePlansUnrecognizedStockBasedCompensationDetails" xlink:type="extended" xlink:title="40704 - Disclosure - Equity Incentive Plans - Unrecognized Stock-Based Compensation (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_636924181061820102" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_636924181061820102" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157445345" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157445345" xlink:to="us-gaap_PlanNameAxis_637244601157445345" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="us-gaap_PlanNameDomain_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameAxis_637244601157445345" xlink:to="us-gaap_PlanNameDomain_637244601157445345" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_EmployeeStockPurchasePlanMember" xlink:label="ardx_EmployeeStockPurchasePlanMember_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain_637244601157445345" xlink:to="ardx_EmployeeStockPurchasePlanMember_637244601157445345" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157445345" xlink:to="us-gaap_AwardTypeAxis_637244601157445345" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis_637244601157445345" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_637244601157445345" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="us-gaap_EmployeeStockOptionMember_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_637244601157445345" xlink:to="us-gaap_EmployeeStockOptionMember_637244601157445345" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_PerformanceBasedRestrictedStockUnitsMember" xlink:label="ardx_PerformanceBasedRestrictedStockUnitsMember_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_637244601157445345" xlink:to="ardx_PerformanceBasedRestrictedStockUnitsMember_637244601157445345" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_637244601157445345" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157445345" order="3" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_637244601157445345" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157445345" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_637244601157445345" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_637244601157445345" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_637244601157594946" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureNetLossPerShareComputationOfBasicAndDilutedLossPerShareAttributableToCommonStockholdersDetails" xlink:type="extended" xlink:title="40801 - Disclosure - Net Loss Per Share - Computation of Basic and Diluted Loss Per Share Attributable to Common Stockholders (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="EarningsPerShareAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetIncomeLossAbstract" xlink:label="us-gaap_NetIncomeLossAbstract_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="EarningsPerShareAbstract" xlink:to="us-gaap_NetIncomeLossAbstract_637244601157594946" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetIncomeLossAbstract_637244601157594946" xlink:to="us-gaap_NetIncomeLoss_637244601157594946" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="EarningsPerShareAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_637244601157594946" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_637244601157594946" xlink:to="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_637244601157594946" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareBasicAndDiluted_637244601157594946" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/positiveLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureNetLossPerShareAdditionalInformationDetails" xlink:type="extended" xlink:title="40802 - Disclosure - Net Loss Per Share - Additional Information (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="EarningsPerShareAbstract" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_AntidilutiveSecuritiesIncludedFromComputationOfEarningsPerShareAmount" xlink:label="ardx_AntidilutiveSecuritiesIncludedFromComputationOfEarningsPerShareAmount_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="EarningsPerShareAbstract" xlink:to="ardx_AntidilutiveSecuritiesIncludedFromComputationOfEarningsPerShareAmount_637244601157594946" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureCollaborationAndLicensingAgreementsAdditionalInformationDetails" xlink:type="extended" xlink:title="40901 - Disclosure - Collaboration and Licensing Agreements - Additional Information (Details)">
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsAbstract" xlink:label="ardx_CollaborationAndLicensingAgreementsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:label="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CollaborationAndLicensingAgreementsAbstract" xlink:to="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157594946" order="1" use="optional" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157594946" xlink:to="us-gaap_TypeOfArrangementAxis_637244601157594946" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_637244601157594946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TypeOfArrangementAxis_637244601157594946" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_637244601157594946" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ResearchCollaborationAndOptionAgreementMember" xlink:label="ardx_ResearchCollaborationAndOptionAgreementMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember_637244601157594946" xlink:to="ardx_ResearchCollaborationAndOptionAgreementMember_637244601157604920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_LicenseAgreementMember" xlink:label="ardx_LicenseAgreementMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember_637244601157594946" xlink:to="ardx_LicenseAgreementMember_637244601157604920" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_LicenseAgreementDevelopmentCommercializationDistributionInJapanMember" xlink:label="ardx_LicenseAgreementDevelopmentCommercializationDistributionInJapanMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_LicenseAgreementMember_637244601157604920" xlink:to="ardx_LicenseAgreementDevelopmentCommercializationDistributionInJapanMember_637244601157604920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_LicenseAgreementCertainSpecificPatentAndPatentApplicationsMember" xlink:label="ardx_LicenseAgreementCertainSpecificPatentAndPatentApplicationsMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_LicenseAgreementMember_637244601157604920" xlink:to="ardx_LicenseAgreementCertainSpecificPatentAndPatentApplicationsMember_637244601157604920" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_LicenseAgreementDevelopmentCommercializationDistributionInChinaMember" xlink:label="ardx_LicenseAgreementDevelopmentCommercializationDistributionInChinaMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_LicenseAgreementMember_637244601157604920" xlink:to="ardx_LicenseAgreementDevelopmentCommercializationDistributionInChinaMember_637244601157604920" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_LicenseAgreementDevelopmentCommercializationDistributionInCanadaMember" xlink:label="ardx_LicenseAgreementDevelopmentCommercializationDistributionInCanadaMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_LicenseAgreementMember_637244601157604920" xlink:to="ardx_LicenseAgreementDevelopmentCommercializationDistributionInCanadaMember_637244601157604920" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_CounterpartyNameAxis" xlink:label="srt_CounterpartyNameAxis_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157594946" xlink:to="srt_CounterpartyNameAxis_637244601157604920" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_CounterpartyNameAxis_637244601157604920" xlink:to="srt_RepurchaseAgreementCounterpartyNameDomain_637244601157604920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_KyowaKirinCo.LtdMember" xlink:label="ardx_KyowaKirinCo.LtdMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_637244601157604920" xlink:to="ardx_KyowaKirinCo.LtdMember_637244601157604920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ShanghaiFosunPharmaceuticalIndustrialDevelopmentMember" xlink:label="ardx_ShanghaiFosunPharmaceuticalIndustrialDevelopmentMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_637244601157604920" xlink:to="ardx_ShanghaiFosunPharmaceuticalIndustrialDevelopmentMember_637244601157604920" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_XuanzhuHKBiopharmaceuticalLimitedMember" xlink:label="ardx_XuanzhuHKBiopharmaceuticalLimitedMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_637244601157604920" xlink:to="ardx_XuanzhuHKBiopharmaceuticalLimitedMember_637244601157604920" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_KnightTherapeuticsIncMember" xlink:label="ardx_KnightTherapeuticsIncMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_637244601157604920" xlink:to="ardx_KnightTherapeuticsIncMember_637244601157604920" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157594946" xlink:to="srt_ProductOrServiceAxis_637244601157604920" order="3" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductOrServiceAxis_637244601157604920" xlink:to="srt_ProductsAndServicesDomain_637244601157604920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_OtherProductOrServicesRevenueMember" xlink:label="ardx_OtherProductOrServicesRevenueMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain_637244601157604920" xlink:to="ardx_OtherProductOrServicesRevenueMember_637244601157604920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157594946" xlink:to="srt_RangeAxis_637244601157604920" order="4" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeMember" xlink:label="srt_RangeMember_637244601157604920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis_637244601157604920" xlink:to="srt_RangeMember_637244601157604920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_637244601157604920" xlink:to="srt_MinimumMember_637244601157614894" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_637244601157604920" xlink:to="srt_MaximumMember_637244601157614894" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:label="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157594946" xlink:to="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" order="5" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_NumberOfPreClinicalStudyReadyCompounds" xlink:label="ardx_NumberOfPreClinicalStudyReadyCompounds_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_NumberOfPreClinicalStudyReadyCompounds_637244601157614894" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_NumberOfCompoundInhibitingFirstUndisclosedTarget" xlink:label="ardx_NumberOfCompoundInhibitingFirstUndisclosedTarget_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_NumberOfCompoundInhibitingFirstUndisclosedTarget_637244601157614894" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_NumberOfDevelopmentCandidates" xlink:label="ardx_NumberOfDevelopmentCandidates_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_NumberOfDevelopmentCandidates_637244601157614894" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_NumberOfSeparateCollaborativeAgreements" xlink:label="ardx_NumberOfSeparateCollaborativeAgreements_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_NumberOfSeparateCollaborativeAgreements_637244601157614894" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsUpfrontPaymentReceivable" xlink:label="ardx_CollaborationAndLicensingAgreementsUpfrontPaymentReceivable_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborationAndLicensingAgreementsUpfrontPaymentReceivable_637244601157614894" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsUpfrontPaymentReceivableFistInstallment" xlink:label="ardx_CollaborationAndLicensingAgreementsUpfrontPaymentReceivableFistInstallment_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborationAndLicensingAgreementsUpfrontPaymentReceivableFistInstallment_637244601157614894" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_TermOfPaymentOfLicenseFeeFirstInstallment" xlink:label="ardx_TermOfPaymentOfLicenseFeeFirstInstallment_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_TermOfPaymentOfLicenseFeeFirstInstallment_637244601157614894" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsUpfrontPaymentReceivableSecondInstallment" xlink:label="ardx_CollaborationAndLicensingAgreementsUpfrontPaymentReceivableSecondInstallment_637244601157614894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborationAndLicensingAgreementsUpfrontPaymentReceivableSecondInstallment_637244601157614894" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_TermOfAgreement" xlink:label="ardx_TermOfAgreement_637244601157624867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_TermOfAgreement_637244601157624867" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsInitialTransactionPrice" xlink:label="ardx_CollaborationAndLicensingAgreementsInitialTransactionPrice_637244601157624867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborationAndLicensingAgreementsInitialTransactionPrice_637244601157624867" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_637244601157624867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_637244601157624867" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="7" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_RevenueFromContractWithCustomerChangeInEstimate" xlink:label="ardx_RevenueFromContractWithCustomerChangeInEstimate_637244601157624867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_RevenueFromContractWithCustomerChangeInEstimate_637244601157624867" order="12" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_TransactionPriceAllocatedToPartiallyUnsatisfiedPerformanceObligations" xlink:label="ardx_TransactionPriceAllocatedToPartiallyUnsatisfiedPerformanceObligations_637244601157624867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_TransactionPriceAllocatedToPartiallyUnsatisfiedPerformanceObligations_637244601157624867" order="13" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_637244601157624867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="us-gaap_ContractWithCustomerLiabilityCurrent_637244601157624867" order="14" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromLicenseFeesReceived" xlink:label="us-gaap_ProceedsFromLicenseFeesReceived_637244601157624867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="us-gaap_ProceedsFromLicenseFeesReceived_637244601157624867" order="15" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerAssetNetCurrent" xlink:label="us-gaap_ContractWithCustomerAssetNetCurrent_637244601157624867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="us-gaap_ContractWithCustomerAssetNetCurrent_637244601157624867" order="16" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborativeArrangementDevelopmentMilestonesPaymentToBeReceived" xlink:label="ardx_CollaborativeArrangementDevelopmentMilestonesPaymentToBeReceived_637244601157634839" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborativeArrangementDevelopmentMilestonesPaymentToBeReceived_637244601157634839" order="17" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborativeArrangementDevelopmentMilestonesPaymentReceived" xlink:label="ardx_CollaborativeArrangementDevelopmentMilestonesPaymentReceived_637244601157634839" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborativeArrangementDevelopmentMilestonesPaymentReceived_637244601157634839" order="18" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborativeArrangementCommercializationMilestonesPaymentToBeReceived" xlink:label="ardx_CollaborativeArrangementCommercializationMilestonesPaymentToBeReceived_637244601157634839" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborativeArrangementCommercializationMilestonesPaymentToBeReceived_637244601157634839" order="19" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsLicenseFee" xlink:label="ardx_CollaborationAndLicensingAgreementsLicenseFee_637244601157634839" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborationAndLicensingAgreementsLicenseFee_637244601157634839" order="20" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsSecondMilestonePayment" xlink:label="ardx_CollaborationAndLicensingAgreementsSecondMilestonePayment_637244601157634839" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborationAndLicensingAgreementsSecondMilestonePayment_637244601157634839" order="21" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborativeArrangementFutureDevelopmentAndCommercializationMilestones" xlink:label="ardx_CollaborativeArrangementFutureDevelopmentAndCommercializationMilestones_637244601157634839" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborativeArrangementFutureDevelopmentAndCommercializationMilestones_637244601157634839" order="22" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ThresholdPercentageOfSalesForTieredRoyalties" xlink:label="ardx_ThresholdPercentageOfSalesForTieredRoyalties_637244601157634839" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_ThresholdPercentageOfSalesForTieredRoyalties_637244601157634839" order="23" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborativeArrangementUpFrontPaymentAndDevelopmentAndSalesMilestonesPaymentToBeReceived" xlink:label="ardx_CollaborativeArrangementUpFrontPaymentAndDevelopmentAndSalesMilestonesPaymentToBeReceived_637244601157634839" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157614894" xlink:to="ardx_CollaborativeArrangementUpFrontPaymentAndDevelopmentAndSalesMilestonesPaymentToBeReceived_637244601157634839" order="24" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureCollaborationAndLicensingAgreementsScheduleOfChangesInDeferredRevenueDetails" xlink:type="extended" xlink:title="40902 - Disclosure - Collaboration and Licensing Agreements - Schedule of Changes in Deferred Revenue (Details)">
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_CollaborationAndLicensingAgreementsAbstract" xlink:label="ardx_CollaborationAndLicensingAgreementsAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:label="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157644812" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ardx_CollaborationAndLicensingAgreementsAbstract" xlink:to="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157644812" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis_637244601157644812" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157644812" xlink:to="us-gaap_TypeOfArrangementAxis_637244601157644812" order="1" use="optional" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_637244601157644812" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TypeOfArrangementAxis_637244601157644812" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_637244601157644812" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ResearchCollaborationAndOptionAgreementMember" xlink:label="ardx_ResearchCollaborationAndOptionAgreementMember_637244601157644812" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember_637244601157644812" xlink:to="ardx_ResearchCollaborationAndOptionAgreementMember_637244601157644812" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:label="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157644812" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_637244601157644812" xlink:to="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157644812" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerLiability" xlink:label="us-gaap_ContractWithCustomerLiability_637244601157644812" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157644812" xlink:to="us-gaap_ContractWithCustomerLiability_637244601157644812" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ContractWithCustomerLiabilityRevenueRecognizedCashReceived" xlink:label="ardx_ContractWithCustomerLiabilityRevenueRecognizedCashReceived_637244601157644812" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157644812" xlink:to="ardx_ContractWithCustomerLiabilityRevenueRecognizedCashReceived_637244601157644812" order="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="ardx-20200331.xsd#ardx_ContractWithCustomerLiabilityRevenueRecognizedCashNotYetReceived" xlink:label="ardx_ContractWithCustomerLiabilityRevenueRecognizedCashNotYetReceived_637244601157644812" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157644812" xlink:to="ardx_ContractWithCustomerLiabilityRevenueRecognizedCashNotYetReceived_637244601157644812" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ContractWithCustomerLiability" xlink:label="us-gaap_ContractWithCustomerLiability_6372446011576448121" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_637244601157644812" xlink:to="us-gaap_ContractWithCustomerLiability_6372446011576448121" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.ardelyx.com/role/DisclosureContingenciesAdditionalInformationDetails" xlink:type="extended" xlink:title="41001 - Disclosure - Contingencies - Additional Information (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LossContingencyAccrualAtCarryingValue" xlink:label="us-gaap_LossContingencyAccrualAtCarryingValue_637244601157644812" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_LossContingencyAccrualAtCarryingValue_637244601157644812" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
  </presentationLink>
</linkbase>
