The commonest site of perforation during colonoscopy is -

• Risks of colonoscopy: Perforation and hemorrhage • MC site of bleeding after colonoscopy: Stalk after polypectomy. • MC site of perforation during colonoscopy: Sigmoid colon • Perforation can be caused by excessive air pressure, tearing of the antimesenteric border of the colon from excessive pressure on colonic loops, and at the sites of electrosurgical applications