Sec Form 4 Filing - MCGUIRE TERRANCE @ IRONWOOD PHARMACEUTICALS INC - 2013-11-07

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person MCGUIRE TERRANCE 2. Issuer Name and Ticker or Trading Symbol IRONWOOD PHARMACEUTICALS INC [ IRWD] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O IRONWOOD PHARMACEUTICALS, INC., 301 BINNEY STREET 3. Date of Earliest Transaction (MM/DD/YY) 11/07/2013 (Street) CAMBRIDGE, MA02142 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Class A Common Stock 11/06/2013 J( 1 ) V 186 A $ 0 2,915 D Class A Common Stock 11/06/2013 J( 1 ) V 106 A $ 0 1,626 I By Polaris Venture Management Co. II, L.L.C. ( 2 ) Class B Common Stock 11/07/2013 S( 3 ) 57 D $ 9.11 0 ( 3 ) I By Polaris Venture Partners Founders' Fund II, L.P. ( 4 ) Class B Common Stock 11/07/2013 S( 5 ) 2,026 D $ 9.11 0 ( 5 ) I By Polaris Venture Partners II, L.P. ( 6 ) Class B Common Stock 40,000 I By Bartlett Partners, LLC ( 7 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other MCGUIRE TERRANCE C/O IRONWOOD PHARMACEUTICALS, INC. 301 BINNEY STREET CAMBRIDGE, MA02142 X Signatures /s/ Halley E. GilbertAttorney-in-Fact 11/08/2013 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Distributed pro rata to the partners of Polaris Venture Partners Founders' Fund II, L.P. without additional consideration in accordance with the partnership agreement of Polaris Venture Partners Founders' Fund II, L.P. In order to effect the distribution, shares of Class B Common Stock were converted into shares of Class A Common Stock in accordance with the issuer's certificate of incorporation. ( 2 )The reporting person is a managing member of Polaris Venture Management Co. II, L.L.C., the beneficial owner of the securities. The reporting person disclaims beneficial ownership of the reported securities, except to the extent of his pecuniary interest therein. ( 3 )In prior reports, the reporting person reported indirect beneficial ownership of 10,455 shares of Class B Common Stock held by Polaris Venture Partners Founders' Fund II, L.P. On November 6, 2013, Polaris Venture Partners Founders' Fund II, L.P. distributed 10,398 shares to its partners without additional consideration in accordance with its partnership agreement. Also, as reported on this form, Polaris Venture Partners Founders' Fund II, L.P. sold 57 shares on November 7, 2013. In order to effect the distribution and sale, shares of Class B Common Stock were converted into shares of Class A Common Stock in accordance with the issuer's certificate of incorporation. ( 4 )The reporting person is a managing member of the general partner of Polaris Venture Partners Founders' Fund II, L.P., the beneficial owner of the securities. The reporting person disclaims beneficial ownership of the reported securities, except to the extent of his pecuniary interest therein. ( 5 )In prior reports, the reporting person reported indirect beneficial ownership of 465,178 shares of Class B Common Stock held by Polaris Venture Partners II, L.P. On November 6, 2013, Polaris Venture Partners II, L.P. distributed 463,152 shares to its partners without additional consideration in accordance with its partnership agreement. Also, as reported on this form, Polaris Venture Partners II, L.P. sold 2,026 shares on November 7, 2013. In order to effect the distribution and sale, shares of Class B Common Stock were converted into shares of Class A Common Stock in accordance with the issuer's certificate of incorporation. ( 6 )The reporting person is a managing member of the general partner of Polaris Venture Partners II, L.P., the beneficial owner of the securities. The reporting person disclaims beneficial ownership of the reported securities, except to the extent of his pecuniary interest therein. ( 7 )The reporting person is a managing member of Bartlett Partners, LLC, the beneficial owner of the securities. The reporting person disclaims beneficial ownership of the securities, except to the extent of his pecuniary interest therein.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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