Flexible Sigmoidoscopy

Flexible sigmoidoscopy is a routine outpatient procedure in which the inner lining of the lower large intestine, called the sigmoid colon, is examined. The procedure is commonly used to evaluate gastrointestinal symptoms, such as abdominal pain, rectal bleeding, or changes in bowel habits. It is also performed to screen people over age 50 for colon and rectal cancer.

During the sigmoidoscopy, a doctor uses a sigmoidoscope, a long, flexible tubular instrument about 1/2 inch in diameter, to view the lining of the rectum and the lower third of the large intestine. The device is inserted through the rectum and passed through the large intestine.

How Do I Prepare for a Sigmoidoscopy?

Before having a sigmoidoscopy, tell your doctor about any medical conditions you may have that he or she may not know about.

You should always tell your doctor if you:

• Have a lung or heart condition.
• Are allergic to any medications.
• Have diabetes or take medications that may affect blood clotting. Adjustments to these medications may be required before the sigmoidoscopy.

Never stop taking any medication without first consulting with your doctor.

You may need to take antibiotics before the sigmoidoscopy if you:

• Have an artificial heart valve.
• Have ever been told you need to take antibiotics before a dental or surgical procedure.

Do I Have to Stop Eating and Drinking Before a Sigmoidoscopy?

There are usually no diet or fluid restrictions before having a sigmoidoscopy. But, your bowel must be cleansed in order for sigmoidoscopy to be successful. In most cases, you will receive 1 or 2 enemas in the rectum before the procedure -- try to hold the enema solution for at least 5 minutes before releasing it. Your doctor may have different instructions for you; check with your doctor before your procedure.

How Is a Sigmoidoscopy Performed?

The procedure is performed by a doctor experienced in sigmoidoscope and lasts from 3 to 10 minutes. No sedation is required during the procedure. Your doctor will have you lie on your left side, with your knees drawn up. The sigmoidoscope is inserted through the rectum and passes slowly into the large intestine. A small amount of air is used to expand the colon so the doctor can see the colon walls. You may feel mild cramping during the procedure, but you can reduce the cramping by taking several slow, deep breaths during the procedure. When the doctor has finished, the sigmoidoscope is slowly withdrawn while the lining of your bowel is carefully examined.

What Happens After a Sigmoidoscopy?

After a sigmoidoscopy:

• 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 growths, or polyps, are found during the procedure, a biopsy (removal of tissue) of the polyp, or polyps, may be taken, or you may be advised to have a complete colon examination by colonoscopy with polyp removal.

Warning About Sigmoidoscopy

Puncture of the colon is a serious although rare -- possible complication of sigmoidoscopy.

If you experience any of the following symptoms, call your doctor immediately:

• Severe abdominal pain.
• Fever and chills.
• Heavy or persistent rectal bleeding (greater than 1 tsp. at a time).

Reviewed by The Cleveland Clinic Department of Gastroenterology.