Flexible sigmoidoscopy

A flexible sigmoidoscopy (sig moi-DOS-kuh-pee) is an exam used to evaluate the lower part of the large intestine (colon). During a flexible sigmoidoscopy exam, a thin, flexible tube (sigmoidoscope) is inserted into the rectum.

A tiny video camera at the tip of the tube allows the doctor to view the inside of the rectum and most of the sigmoid colon — about the last two feet (61 centimeters) of the large intestine. If necessary, tissue samples (biopsies) can be taken through the scope during a flexible sigmoidoscopy exam.

Flexible sigmoidoscopy doesn't allow the doctor to see the entire colon. As a result, any cancers or polyps farther into the colon can't be detected with flexible sigmoidoscopy alone.


Why it's done Risks How you prepare What you can expect Results

Your doctor may recommend a flexible sigmoidoscopy exam to:

  • Investigate intestinal signs and symptoms. A flexible sigmoidoscopy exam can help your doctor explore possible causes of abdominal pain, rectal bleeding, changes in bowel habits, chronic diarrhea and other intestinal problems.
  • Screen for colon cancer. If you're age 50 or older and you have no colon cancer risk factors other than age — which puts you at average risk — your doctor may recommend a flexible sigmoidoscopy exam every five years to screen for colon cancer.

    Sigmoidoscopy is one option for colon cancer screening, but there are other options that allow visualization of the whole colon. Talk with your doctor about your options.

© 1998-2015 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of use