A colonoscope is a medical instrument that permits examination of the interior of the colon, as well as the rectum. The colonoscope is a very flexible tube, equipped with a mini video-camera at its tip. It is introduced into the colon by the anus, under local anesthesia or sometimes general anesthesia, the patient thus being completely asleep. Beforehand, the intestines are cleaned by the ingestion of a preparation which empties them of all material. Images of the colon's interior are transmitted live to a screen. This exam is called a colonoscopy and allows the study of the colon's inner wall, called the mucus membrane, as well as the diagnosis of chronic inflammatory illnesses such as Crohn's disease or ulcerative colitis, the discovery of polyps and possibly their removal, and colon cancer research.