3 The procedure
3.1 Full thickness endoscopic bowel excision uses a full thickness resection device. This comprises a modified snare to remove the polyp and deeper layers of the bowel wall, and a clasp device that closes the full thickness of the bowel wall to prevent perforation. The device is attached to the end of a standard endoscope and advanced through the colon until the polyp is identified. The polyp is grasped at its centre and slowly pulled into the cap of the device. An 'over-the-scope' clip is released, closing the site of a potential defect in the bowel wall. A snare is simultaneously placed around the polyp, which is retrieved for histological analysis after the clip is deployed. After removal of the polyp, the colonoscope is re‑inserted and the surgical site is examined for signs of haemorrhage and to check that the clip has closed the bowel wall.
3.2 The procedure is usually done with the patient under sedation but sometimes general anaesthesia is needed.