Ownership Submission
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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(Print or Type Responses)
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)
12/31/2018
(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 12/31/2018   J(1)   4,696,917 D (1) 0 D  
Class A Common Stock 12/31/2018   J(1)   4,696,917 A (1) 4,696,917 D  
Class A Common Stock               4,850 I The 2000 Trust for Malcolm Paul Hecht (2)
Class A Common Stock               4,850 I The 2000 Trust for Zoe Niovi Hecht (2)
Class A Common Stock               4,850 I The 2000 Trust for Alexis Mae Hecht (2)

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) $ 4.89 12/31/2018   J(3)     110,000   (4) 02/11/2019 Class B Common Stock 110,000 (3) 0 D  
Employee Stock Option (Right to Buy) $ 4.89 12/31/2018   J(3)   110,000     (4) 02/11/2019 Class A Common Stock 110,000 (3) 110,000 D  
Employee Stock Option (Right to Buy) $ 5.48 12/31/2018   J(3)     40,000   (5) 07/28/2019 Class B Common Stock 40,000 (3) 0 D  
Employee Stock Option (Right to Buy) $ 5.48 12/31/2018   J(3)   40,000     (5) 07/28/2019 Class A Common Stock 40,000 (3) 40,000 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/ Conor Kilroy, Attorney-In-Fact   01/03/2019
**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) On December 31, 2018, each share of the Issuer's outstanding Class B Common Stock automatically converted into one share of the Issuer's Class A Common Stock pursuant to the Issuer's certificate of incorporation.
(2) 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.
(3) In connection with the conversion described in footnote (1), outstanding stock options granted pursuant to the Issuer's equity incentive plans in respect of the Issuer's Class B Common Stock remain unchanged, except that they now represent the right to receive shares of Class A Common Stock rather than shares of Class B Common Stock.
(4) The option vested as to 1.25% of the shares of Class B Common Stock on each monthly anniversary of January 1, 2009 for the first 36 months, and vested as to 4.5833% of the shares of Class B Common Stock on each monthly anniversary thereafter. The option was fully vested as of January 1, 2013
(5) On July 29, 2009, the Reporting Person was granted an option to purchase 40,000 shares of Class B Common Stock. The option vests in two equal installments upon the Issuer's achievement of certain regulatory and commercial milestones. The option has vested as to 20,000 shares as of the date hereof.

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