Sec Form 4 Filing - FMR LLC @ IRONWOOD PHARMACEUTICALS INC - 2013-03-28

Insider filing report for Changes in Beneficial Ownership
"Insiders might sell their shares for any number of reasons, but they buy them for only one: they think the price will rise"
- Peter Lynch
What is insider trading>>
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
OMB APPROVAL
OMB Number: 3235-0287
Expires: November 30, 2011
Estimated average burden hours per response... 0.5
1. Name and Address of Reporting Person
FMR LLC
2. Issuer Name and Ticker or Trading Symbol
IRONWOOD PHARMACEUTICALS INC [ IRWD]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director X __ 10% Owner
_____ Officer (give title below) X __ Other (specify below)
Edward C. Johnson 3d
(Last) (First) (Middle)
245 SUMMER STREET
3. Date of Earliest Transaction (MM/DD/YY)
03/28/2013
(Street)
BOSTON, MA02210
4. If Amendment, Date Original Filed (MM/DD/YY)
6. Individual or Joint/Group Filing (Check Applicable Line)
_____ Form filed by One Reporting Person
__ X __ 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 03/28/2013 S 158,068 D $ 18.4005 837,736 I See footnote ( 1 )
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
FMR LLC
245 SUMMER STREET
BOSTON, MA02210
X Edward C. Johnson 3d
FIL Ltd
P.O. BOX H.M. 670
HAMILTON, D000000
X Edward C. Johnson 3d
Signatures
Scott C. Goebel, Duly authorized under Powers of Attorney effective as of June 1, 2008, by and on behalf of FMR LLC and its direct and indirect subsidiaries, by and on behalf of Edward C. Johnson 3d, and by and on behalf of FIL Limited 04/02/2013
Signature of Reporting Person Date
Explanation of Responses:
( 1 )Column 5 Amount of Securities Beneficially Owned Following Reported Transaction is held by Fidelity Biosciences Corp. (10,971 Class A Common Stock) and FIL Limited (826,765 Class A Common Stock). Column 5 does not include shares beneficially owned by Fidelity Management & Research Company as a result of acting as investment adviser to various investment companies as disclosed in Remark 1 below.

Remarks:
Remark 1: Fidelity Management & Research Company, a wholly owned subsidiary of FMR LLC and an investment adviser registered under the Investment Advisers Act of 1940, is the beneficial owner of Class A Common Stock of Ironwood Pharmaceuticals Inc. as a result of acting as investment adviser to various investment companies registered under the Investment Company Act of 1940. FMR LLC, Edward C. Johnson 3d and FIL Limited have no pecuniary interest in the Class A Common Stock beneficially owned by Fidelity Management & Research Company. Remark 2: FIL Limited directly holds 826,765 shares of Class A Common Stock of Ironwood Pharmaceuticals Inc. FMR LLC and FIL are of the view that they are not acting as a "group" for purposes of Section 13(d) under the Securities Exchange Act of 1934 (the "1934 Act") and that they are not otherwise required to attribute to each other the "beneficial ownership" of securities "beneficially owned" by the other corporation within the meaning of Rule 16a-1 promulgated under the 1934 Act. Therefore, they are of the view that the shares held by the other corporation need not be aggregated for purposes of Section 16(a). However, FMR LLC is making this filing on a voluntary basis as if all of the shares are beneficially owned by FMR LLC and FIL on a joint basis.

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).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.