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 *
Mallon Mark
   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)
04/01/2019
(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 A Common Stock 04/01/2019   A   11,500 A (1) 104,536 D  
Class A Common Stock 04/01/2019   A(2)   206,873 A $ 0 311,409 D  

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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) $ 10.97 (3) 04/01/2019   A   21,203 (3)     (4) 01/09/2029 Class A Common Stock 21,203 (3) 192,729 D  
Employee Stock Option (Right to Buy) $ 14.02 04/01/2019   A   423,049     (5) 04/01/2029 Class A Common Stock 423,049 $ 0 423,049 D  

Reporting Owners

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

Signatures

 /s/ Conor Kilroy, Attorney-in-Fact   04/03/2019
**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) In connection with the separation (the "Separation") of Cyclerion Therapeutics, Inc. from Ironwood Pharmaceuticals, Inc. ("Ironwood"), the reporting person received 11,500 restricted stock units as a result of the adjustment of existing Ironwood restricted stock units held by the reporting person prior to the Separation. The restricted stock units are subject to vesting conditions consistent with the terms of the existing Ironwood restricted stock units held by the reporting person prior to the Separation.
(2) The restricted stock unit award, granted as a new hire award to the new Chief Executive Officer, vests as to 25% of the shares of Class A Common Stock on each approximate anniversary of the grant thereof.
(3) Represents options to purchase Ironwood Class A Common Stock awarded to the reporting person prior to the Separation. In connection with the Separation, the number of shares subject to this option and the exercise price have been adjusted to preserve the pre-Separation intrinsic value of the existing Ironwood option award.
(4) The option, granted as a new hire award, vests as to 25% of the shares of Class A Common Stock on the first anniversary of January 4, 2019 and 1/48th of the shares of Class A Common Stock vest each month thereafter for the next 36 months.
(5) The option, granted as a new Chief Executive Officer award, vests as to 25% of the shares of Class A Common Stock on the first anniversary of January 4, 2019 and 1/48th of the shares of Class A Common Stock vest each month thereafter for the next 36 months.

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