What is flexible sigmoidoscopy?
Flexible sigmoidoscopy is a routine outpatient procedure in which the inside of the lower large intestine (called the sigmoid colon) is examined.
Flexible sigmoidoscopy is commonly used to evaluate bowel disorders, rectal bleeding, or polyps (usually benign growths).
Sigmoidoscopy is also performed to screen people over age 50 for colon and rectal cancer.
During the procedure, a physician uses a sigmoidoscope to view the lining of the rectum and the lower large intestine. A sigmoidoscope is a long, flexible instrument about 1.27cm (1/2 inch) in diameter, with a light and tiny camera at its end. The instrument is inserted through the rectum and advanced to the large intestine.
How do I prepare for flexible sigmoidoscopy?
Your bowel has to be cleansed thoroughly so your physician can clearly view the lining of your lower intestine. Your physician will give you written instructions on how to do this at home.
Some instructions can vary, depending on the patient's situation or physician's preference. It is important to complete the prep or your doctor may not be able to accurately examine your bowel.
The night before your procedure you will likely need to drink a large amount of liquid laxative, taken at certain times, to clean your bowel. The laxative loosens stools and causes frequent bowel movements. You will need to be close to a bathroom during the sigmoidoscopy prep.
You will also need to follow a clear liquid diet during the prep. You may consume or drink:
- Water
- Fat-free broth or bouillon
- Sports drinks (light colors, not red or purple)
- Gelatin (light colors, such as lemon, lime, and orange)
- Plain coffee or tea, no creamer
- Strained fruit juice (apple or white grape, NOT orange)
Your doctor's office should give you complete instructions on your prep, but do not hesitate to ask if you have any questions.
What happens during a flexible sigmoidoscopy?
Here is what happens during the procedure (which should last from 3 to 10 minutes):
- You will lie on your left side, with your knees drawn up.
- The sigmoidoscope is inserted into the anus, through the rectum and advanced to the large intestine.
- A small amount of air is used to expand the colon so the physician can see the colon walls.
- You may feel mild cramping during the procedure. Cramping can be reduced by taking several slow, deep breaths.
- The sigmoidoscope is slowly withdrawn while the lining of your bowel is carefully examined.
What are the risks of a flexible sigmoidoscopy?
Minor, self-limited bleeding from irritation of the colon lining is the most common risk. Perforation, or tear in the lining of the intestine is an uncommon but serious risk of flexible sigmoidoscopy. Bleeding may occur in cases where polyps are removed. Your physician can usually treat the bleeding immediately. A perforation may need to be treated with a later surgery. Ask your doctor for more information about these risks if you have concerns.
What happens after the procedure?
- Your physician will discuss the results of the sigmoidoscopy with you.
- You may feel some cramping or a sensation of having gas, but this usually passes quickly.
- You may resume your normal diet and activities.
- If polyps were found during the procedure, you may be advised to have a complete colon examination or colonoscopy.
- If you experience severe abdominal pain, fever, chills or heavy rectal bleeding (greater than 1 tsp. at a time), please call your doctor.