Apparatus and methods for endoscopic colectomy are described herein. A colectomy device having a first and a second tissue approximation device is mounted on a colonoscope separated from one another. During deployment of the colectomy device, a diseased portion of the colon is positioned inbetween the tissue approximation devices. The tissue approximation devices are radially expanded such that they contact and grasp the colon wall at two sites adjacent to the diseased portion of the colon. The diseased portion is separated from the omentum and is transected using a laparoscope or is drawn into the colonoscope for later removal. The tissue approximation devices are then urged towards one another over the colonoscope to approximate the two free edges of the colon into contact together where they are fastened to one another using the tissue approximation device as a surgical stapler to create an end-to-end anastomosis.