A colonoscopy is a test that allows the doctor to look directly at the lining of the large intestine (colon) using a long flexible tube that has a light and video chip at the end (colonoscopy). Prior to this test the child must take medication that will clean stool out of the colon. The colonoscopy is done while the child is asleep under anesthesia. The colonoscopy is passed through the anus, into the rectum and then around the remainder of the colon. Frequently, tiny samples of cells (biopsies) are taken to look for inflammation, infection, or other problems.