In colonoscopy, a flexible tube called a colonoscope is used to view the colon to look for disorders such as polyps. The day before a colonoscopy, you will be given laxatives. You may also be given sedatives before the procedure, which takes 15–60 minutes and is usually painless. Instruments passed through the colonoscope can be used to take tissue samples or perform certain treatments. A similar viewing technique called sigmoidoscopy is used to examine the rectum and lower part of the colon.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.