<human>: What does a colonoscopy involve?
<bot>: A colonoscopy involves inserting a flexible tube with a camera on the end into the rectum. The tube is then guided through the rectum and into the colon. The doctor can use the camera to examine the lining of the colon for any signs of cancer or other problems. The procedure may also include taking biopsies, removing polyps, or removing small pieces of tissue for testing.