Document and Entity Information	6 Months Ended
	Jun. 30, 2011	Aug. 01, 2011 Class A common stock	Aug. 01, 2011 Class B common stock
Entity Registrant Name	IRONWOOD PHARMACEUTICALS INC
Entity Central Index Key	0001446847
Document Type	10-Q
Document Period End Date	Jun. 30, 2011
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		56,472,788	43,849,074
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2