Colonoscopy is a diagnostic technique which aims at viewing the inner lining of  the rectum and colon and this is done by means of a colonoscope. A colonoscope is a thin, elongated, pliable tube, 48 to 72 inches long, that aids in diagnosing polyps, ulcers, tumors, and places of swelling such as, abnormal growth, peptic ulcer and tissue swelling and rectal bleeding. Early symptoms of colonal and rectal cancer and precancerous development are detected by colonoscopy. The reason behind changes in bowel movements accompanied by loss of weight is identified. It is also used to diagnose and eliminate precancerous developments of colon and rectum.

Colonoscopy

Any malfunctioning of the abdomen resulting in indigestion and Diarrhea, and is detected  in an x-ray is further investigated. This investigation colonoscopy procedure is especially recommended for people, whose probability of getting colon cancer or polyps is more and in people, who have suffered in the past. Photographic or video images of the intestine are taken by the attached camera of the colonoscope, thereby providing a vivid picture of the area of malfunctioning. Fiber op[tics are sometimes made use of, though, modern science has substituted them for digital video technology. Sigmoidoscopy projects the rectum and the lower colon, whereas, colonoscopy visualizes the whole of the colon and a minor part of the small intestine.

This diagnostic procedure requires almost an hour for complete evaluation. The analgesics and tranquilizers,whose effect remains for an hour aids in providing relief from pain and soreness. A sensation of flatulence is experienced for an hour, after colonoscopy. Prior to colonoscopy, colon preparation requires 1-2 days. It is a very tiring procedure, as it involves complete removal of bowels. Staying at home, during pre-preparation is advised, as frequent visits to the toilet is necessitated. A clear liquid diet is recommended and hence, hunger is greatly experienced. This procedure is a great discomfort, as frequent loose stool evacuation is done, resulting in an empty stomach. Clear fruit juices and soft drinks are recommended, as a pre-preparation procedure.

Virtual colonoscopy is a non-invasive diagnostic technique that utilizes a modified version of the nuclear magnetic resonance (NMR) or computed tomography (CT), thereby making use of two and three dimensional images in deriving an image of the rectal and anal lining. The causative factor of a tumor, swelling and incontinence is identified. Small lesions or bruises, less than 5 millimeters cannot be visualized. Virtual colonoscopy does not facilitate the removal of tumor or biopsy. This method requires about an hour before bowel cleansing.