Flexible sigmoidoscopy: screening for colorectal cancer

What is flexible sigmoidoscopy?

This test allows your health care provider to closely check the lining of the rectum and part of the colon (large bowel). A flexible tube (about the thickness of your finger) is passed into the anus and advanced slowly into the rectum and sigmoid colon.

What preparation is needed for this test?

The rectum and lower colon must be empty of waste material for the test to be accurate and complete. You will be given detailed instructions on how to cleanse your bowel before the test. You may also be asked to make changes in your diet for a short time.

Be sure to remind your health care provider about:

  • The medications you take regularly. This is especially important if you take an anticoagulant ("blood thinner") or aspirin.
  • Any allergies you have.
  • If you take antibiotics before dental or other procedures.

What can you expect during the test?

You should not feel pain, but you may feel as if you need to move your bowels. You may also feel cramping or pressure from the air that is put into your bowel through the tube (sigmoidoscope). You will be asked to lie on your side, or on a special table in a knee-to-chest position.

What if the test shows something abnormal?

If an area needs to be looked at more closely, a biopsy (sample of the colon lining) may be taken and sent to a lab for further testing.

What can you expect after the test?

Your health care provider will explain the results to you. Any cramping or bloating you feel should disappear quickly when you pass gas. You should be able to eat and resume normal activities when you leave the doctor's office or hospital. You may have small amounts of bleeding from your rectum for several days.

Complications after flexible sigmoidoscopy are rare. Be sure to call your health care provider if you have severe pain, fever, or more than small amounts of rectal bleeding.

DISCLAIMER: The information presented in this site is intended for general information and educational purposes. It is not intended to replace the advice of your own physician. Contact your physician if you believe you have a health problem.