Sigmoidoscopy differs from colonoscopy in that your doctor is limited to examining only your rectum and the lower part of the large intestine, which is called the sigmoid colon. In a colonoscopy, the entire large intestine is examined. The other difference between the two procedures is that no sedation is needed for a sigmoidoscopy.

Types of Procedures

There are two types of sigmoidoscopy procedures

• Flexible sigmoidoscopy
• Rigid sigmoidoscopy

The difference between the two has to do with the type of scope used, either a flexible or rigid tube. Rigid sigmoidoscopy is now rarely used because of the improved technology of flexible sigmoidoscopy. Preparation for a sigmoidoscopy procedure is simple and you will be given an enema before the procedure. During the procedure, you will be asked to lie down on your left side. A short, lighted tube, called a sigmoidoscope, is inserted into the rectum. The tube fills the area with air and takes a video image that your doctor can examine. The scope can remove polyps and take biopsy samples of abnormal tissue, both of which will then be sent to a laboratory to rule out the presence of cancer. The procedure takes approximately 10 minutes.