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 OF SECURITIES 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 * Hecht Peter M   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 __X__ Officer (give title below) _____ Other (specify below) Chief Executive Officer (Last) (First) (Middle) C/O IRONWOOD PHARMACEUTICALS, INC., 301 BINNEY STREET 3. Date of Earliest Transaction (Month/Day/Year) 10/28/2015 (Street) CAMBRIDGE, MA 02142 4. If Amendment, Date Original Filed(Month/Day/Year) 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 B Common Stock 10/28/2015   M   29,102 A $ 1.56 4,170,519 D   Class B Common Stock 10/28/2015   M   35,000 A $ 1.56 4,205,519 D   Class B Common Stock 10/28/2015   M   34,013 A $ 2.94 4,239,532 D   Class A Common Stock               73,418 D   Class A Common Stock               4,850 I The 2000 Trust for Malcom Paul Hecht (1) Class A Common Stock               4,850 I The 2000 Trust for Zoe Niovi Hecht (1) Class A Common Stock               4,850 I The 2000 Trust for Alexis Mae Hecht (1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

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 (Month/Day/Year)

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

Employee Stock Option (Right to Buy)

$ 1.56

10/28/2015

M

29,102

(2)

03/14/2016

Class B Common Stock

29,102

$ 0

550,790

D

Employee Stock Option (Right to Buy)

$ 1.56

10/28/2015

M

35,000

(3)

03/13/2016

Class B Common Stock

35,000

$ 0

0

D

Employee Stock Option (Right to Buy)

$ 2.94

10/28/2015

M

34,013

(4)

01/22/2017

Class B Common Stock

34,013

$ 0

65,987

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Hecht Peter M C/O IRONWOOD PHARMACEUTICALS, INC. 301 BINNEY STREET CAMBRIDGE, MA 02142	X		Chief Executive Officer

Signatures

/s/ Mark Gaffney, Attorney-in-Fact		10/29/2015
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	These shares are held in the referenced trust for the benefit of the reporting person's child. The reporting person's spouse is the trustee of this trust. The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or any other purpose.
(2)	The option vests upon the earlier of (i) the issuer's achievement of certain regulatory, commercial and market capitalization milestones and (ii) January 1, 2016. Upon achievement of a regulatory milestone on October 24, 2011 and a commercial milestone on December 21, 2012, the option vested as to 400,000 and 300,000 shares of Class B Common Stock, respectively.
(3)	The option vested as to 1.25% of the shares of Class B Common Stock on each monthly anniversary of January 1, 2006 for the first 36 months, and as to 4.5833% of the shares of Class B Common Stock each monthly anniversary thereafter. The option was fully vested as of January 1, 2010.
(4)	The option vested as to 1.25% of the shares of Class B Common Stock on each monthly anniversary of January 1, 2007 for the first 36 months, and as to 4.5833% of the shares of Class B Common Stock each monthly anniversary thereafter. The option was fully vested as of January 1, 2011.
Remarks: Exhibit 24: Power of Attorney

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