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 *
Gilbert Halley E
   2. Issuer Name and Ticker or Trading Symbol
IRONWOOD PHARMACEUTICALS INC [IRWD] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Legal 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 A Common Stock               142,423 (1) 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) $ 4.89 12/31/2018   J(2)     20,449   (3) 02/11/2019 Class B Common Stock 20,449 (2) 0 D  
Employee Stock Option (Right to Buy) $ 4.89 12/31/2018   J(2)   20,449     (3) 02/11/2019 Class A Common Stock 20,449 (2) 20,449 D  
Employee Stock Option $ 5.48 12/31/2018   J(2)     20,000   (4) 07/28/2019 Class B Common Stock 20,000 (2) 20,000 D  
Employee Stock Option $ 5.48 12/31/2018   J(2)   20,000     (4) 07/29/2019 Class A Common Stock 20,000 (2) 20,000 D  
Employee Stock Option $ 5.48 12/31/2018   J(2)     20,000   (5) 07/29/2019 Class A Common Stock 20,000 (2) 20,000 D  
Employee Stock Option $ 5.48 12/31/2018   J(2)   20,000     (5) 07/29/2019 Class A Common Stock 20,000 (2) 20,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Gilbert Halley E
C/O IRONWOOD PHARMACEUTICALS, INC.
301 BINNEY STREET
CAMBRIDGE, MA 02142		       Chief Legal 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) The Reporting Person acquired a total of 524 shares of Class A Common Stock under the Issuer's employee stock purchase plan on December 31, 2018.
(2) 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. In connection with the conversion, 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.
(3) 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.
(4) On July 29, 2009, the Reporting Person was granted an option to purchase 20,000 shares of Class B Common Stock upon the Issuer's achievement of certain regulatory milestones. The option has vested as to 20,000 shares as of the date hereof.
(5) On July 29, 2009, the Reporting Person was granted an option to purchase 20,000 shares of Class B Common Stock upon the Issuer's achievement of commercial milestones. The option has not vested as to any shares as of the date hereof.

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