Sometimes it is necessary for the doctor to introduce air into the colon to improve visibility. Before sigmoidoscopy, the colon must be clear of stool to ensure good visibility. The patient must undergo a preparation that may include a liquid diet, enema, and laxatives to clear stool from the colon. A colonoscopy is an examination of the rectum and the entire colon. It is performed with a lighted, flexible, hollow tube.
Colonoscopy permits the physician to visualize the entire colon.
Before having a colonoscopy the colon must be clear to ensure good visibility. The patient must undergo a preparation that may include a liquid diet, enema, and laxatives to clear stool from the colon. The patient is sedated before the colonoscopy begins. Many people sleep through the entire procedure and feel little or no discomfort. The insertion of air during the procedure may cause some discomfort.