Sigmoidoscopy

What is sigmoidoscopy?

Sigmoidoscopy is an exam of the lower part of the colon (large intestine, or bowel) with a slim, flexible, lighted tube called a sigmoidoscope. The scope is passed into the rectum and slowly advanced into the lower part of the large intestine, known as the sigmoid colon.

An instrument called a rigid sigmoidoscope is used less often than the flexible tube because the flexible tube is more comfortable and allows your health care provider to see more of the colon. The flexible sigmoidoscope allows your provider to look inside about one half of the colon.

When is it used?

Sigmoidoscopy may be done to screen for cancer of the colon or rectum when you have no symptoms but are at risk for this type of cancer. Also, it may be used to help diagnose diarrhea, bleeding, pain, or inflammation in the rectum.

An alternative to this procedure is a colonoscopy. A colonoscope is longer and allows examination of the full length of the colon to the appendix area.

How do I prepare for sigmoidoscopy?

Follow your health care provider's instructions about not smoking before and after the procedure.

If you need a minor pain reliever in the week before the procedure, choose acetaminophen rather than aspirin, ibuprofen, or naproxen. This helps avoid extra bleeding during surgery. If you are taking daily aspirin for a medical condition, ask your provider if you need to stop taking it before the procedure.

Your provider may ask you to restrict your diet beginning the day before the procedure. You may be asked to take a liquid laxative or to give yourself an enema at home just before the procedure. You may be given an enema at your provider's office 30 minutes to 1 hour before the procedure. For an enema, fluid is forced into your rectum to cause a bowel movement.

Tell your provider if:

You have any allergies.
You are taking any medicines, especially aspirin or anticoagulants (blood thinners).
You need to take antibiotics before dental procedures because of heart valve disease or implanted devices, such as artificial joints.

In some cases, your health care provider may prescribe antibiotics for you to take before the procedure.

What happens during the procedure?

The procedure is done in your health care provider's office and does not require anesthesia. Usually you lie down on your left side with your knees bent and drawn up to your stomach. Before the sigmoidoscope is inserted into your rectum, the tip of the scope is lubricated to cause less discomfort. Your health care provider can use the scope to force air inside the intestine if necessary to see better. Your provider can view the images of the colon on a TV monitor.

If a polyp or cancer is found, your provider will recommend a colonoscopy. Polyps and abnormal tissue can then be removed and tested in the lab. Your provider will also be able to examine the full length of the colon.

The exam takes about 10 to 20 minutes.

What happens after the procedure?

After the test, it is normal to feel some bloating or cramping. You will also need to pass gas to get rid of the extra air that was pumped into the intestines during the test. Walking may help relieve the discomfort.

Unless your health care provider tells you otherwise, there are no special measures to take after the procedure.

What are the benefits of this procedure?

This procedure helps your health care provider diagnose problems in the colon. For some of these problems, such as cancer, treatment is more effective when the problem is detected early.

What are the risks associated with this procedure?

Risks include:

damage to the colon (perforation) by the sigmoidoscope
bleeding or infection inside the colon
some pain or swelling in your lower abdomen if air was added into your intestine during the procedure (this will last until your body passes the extra air shortly after the procedure).

When should I call my health care provider?

Call your health care provider right away if:

You have severe abdominal pain after the procedure.
You have a fever.
Pain or symptoms you had earlier become worse.

Call your health care provider during office hours if:

You have questions about the procedure or its result.
You want to make another appointment.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File TST5131F.HTM Release 9.0/2006