X0203 3 2010-02-02 0 0001446847 IRONWOOD PHARMACEUTICALS INC IRWD 0001239242 ROBERTS BRYAN E C/O IRONWOOD PHARMACEUTICALS, INC. 320 BENT STREET CAMBRIDGE MA 02141 1 0 1 0 Class B Common Stock 15000 D Class B Common Stock 2559605 I By Venrock Associates Class B Common Stock 3683329 I By Venrock Associates II, L.P. Class B Common Stock 48387 I By Venrock Entrepreneurs Fund, L.P. Class B Common Stock 2017021 I By Venrock Healthcare Capital Partners, LP Class B Common Stock 382979 I By VHCP Co-Investment Holdings, LLC Class B Common Stock 40000 I By VR Management, LLC Consists of shares held directly by Venrock Associates. The Reporting Person is a general partner of Venrock Associates and may be deemed to beneficially own these shares. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. Consists of shares held directly by Venrock Associates II, L.P ("Venrock Associates II"). The Reporting Person is a general partner of Venrock Associates II and may be deemed to beneficially own these shares. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. Consists of shares held directly by Venrock Entrepreneurs Fund, L.P. ("Venrock Entrepreneurs"). Venrock Management, LLC ("Venrock Management") is the general partner of Venrock Entrepreneurs and may be deemed to beneficially own these shares. The Reporting Person is a member of Venrock Management and may be deemed to beneficially own these shares. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. Consists of shares held directly by Venrock Healthcare Capital Partners, LP ("VHCP LP"). VHCP Management, LLC ("VHCP Management") is the general partner of VHCP LP and may be deemed to beneficially own these shares. The Reporting Person is a member of VHCP Management and may be deemed to beneficially own these shares. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. Consists of shares held directly by VHCP Co-Investment Holdings, LLC ("VHCP Co-Investment"). VHCP Management is the manager of VHCP Co-Investment and may be deemed to beneficially own these shares. The Reporting Person is a member of VHCP Management and may be deemed to beneficially own these shares. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. Consists of shares held directly by VR Management, LLC ("VR Management"). The Reporting Person is a member of VR Management and may be deemed to beneficially own these shares. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. Exhibit 24 - Power of Attorney Halley Gilbert, Attorney-in-Fact 2010-02-02