<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001321402</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001437402</issuerCik>
            <issuerName>ARDELYX INC</issuerName>
            <secFileNumber>001-36485</secFileNumber>
            <issuerAddress>
                <ns2:street1>400 Fifth Avenue Suite 210</ns2:street1>
                <ns2:city>Waltham</ns2:city>
                <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                <ns2:zipCode>02451</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>6176752739</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>MICHAEL RAAB</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Director</relationshipToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>125000</noOfUnitsSold>
            <aggregateMarketValue>711250.00</aggregateMarketValue>
            <noOfUnitsOutstanding>247029387</noOfUnitsOutstanding>
            <approxSaleDate>06/15/2026</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/15/2026</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of Stock Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>62500</amountOfSecuritiesAcquired>
            <paymentDate>06/15/2026</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>08/19/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>58795</amountOfSecuritiesAcquired>
            <paymentDate>08/19/2024</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/29/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Employee Stock Purchase Plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>3705</amountOfSecuritiesAcquired>
            <paymentDate>02/29/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>MICHAEL G. RAAB</name>
                <address>
                    <ns2:street1>400 Fifth Avenue Suite 210</ns2:street1>
                    <ns2:city>Waltham</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02451</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/21/2026</saleDate>
            <amountOfSecuritiesSold>54748</amountOfSecuritiesSold>
            <grossProceeds>343133.09</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for MICHAEL G. RAAB</name>
                <address>
                    <ns2:street1>400 Fifth Avenue Suite 210</ns2:street1>
                    <ns2:city>Waltham</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02451</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2026</saleDate>
            <amountOfSecuritiesSold>41666</amountOfSecuritiesSold>
            <grossProceeds>261610.40</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for MICHAEL G. RAAB</name>
                <address>
                    <ns2:street1>400 Fifth Avenue Suite 210</ns2:street1>
                    <ns2:city>Waltham</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02451</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>04/15/2026</saleDate>
            <amountOfSecuritiesSold>41668</amountOfSecuritiesSold>
            <grossProceeds>261954.22</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for MICHAEL G. RAAB</name>
                <address>
                    <ns2:street1>400 Fifth Avenue Suite 210</ns2:street1>
                    <ns2:city>Waltham</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02451</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>03/16/2026</saleDate>
            <amountOfSecuritiesSold>41666</amountOfSecuritiesSold>
            <grossProceeds>243329.44</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale.
The securities to be sold were acquired upon the vesting of restricted stock units during the period of 08/19/2024 through 02/19/2025
The securities to be sold were acquired upon the purchase of employee stock purchase plan shares during the period of 02/29/2024 through 02/28/2025.
</remarks>
        <noticeSignature>
            <noticeDate>06/15/2026</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>11/07/2025</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Michael Raab</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
