Colonoscopy procedure. Artwork and photograph illustrating the process of colonoscopy,the use of an endoscope to view the colon (part of the large intestine). The tip of the colonoscope (lower left) includes a video camera lens,a light,a water jet for irrigation,and an instrument channel. The colonoscope is inserted through the anus and along the rectum into the colon. In the main artwork (frontal,anterior view),it is shown inserted through the four main parts of the colon,the sigmoid colon,the descending colon,the transverse colon,and the ascending colon. The visual output is observed by the surgeon on a monitor (upper left) |