Sigmoidoscopy (Anoscopy, Proctoscopy)

Anoscopy, Flexible Sigmoidoscopy, Proctoscopy

Test Overview

Anoscopy, proctoscopy, and sigmoidoscopy tests allow your health professional to look at the inner lining of your anus, rectum, and the lower part of the large intestineClick here to see an illustration. (colon). These tests are used to look for abnormal growths (such as tumours or polyps), inflammation, bleeding, hemorrhoids, and other conditions (such as diverticulosis).

These test use different scopes look at different sections of the colon.

  • Anoscopy. During an anoscopy, a short, rigid, hollow tube (anoscope) that may contain a light source is used to look at the last 5 cm (2 in.) of the colon (anal canal). Anoscopy can usually be done at any time because it does not require any special preparation (enemas or laxatives) to empty the colon.
  • Proctoscopy. During a proctoscopy, a slightly longer instrument than the anoscope is used to view the inside of the rectum. You usually will have to use enemas or laxatives to empty the colon before the test is done.
  • Sigmoidoscopy. During a sigmoidoscopy, a lighted tube that may be either rigid or flexible is inserted through the anus. Your health professional can remove small growths and collect tissue samples (biopsy) through a sigmoidoscope. You will have to use enemas or laxatives (or both) to empty the colon before the test is done.
    • The flexible sigmoidoscope is about 70 cm (2.3 ft) long and 1 cm (0.5 in.) wide with a lighted lens system. This instrument allows your health professional to see around bends in the colon. A flexible sigmoidoscope allows a more complete view of the lower colon than a rigid scope and usually makes the examination more comfortable. The flexible sigmoidoscope generally has replaced the rigid sigmoidoscope.
    • The rigid sigmoidoscope is used less often. It is about 25 cm (10 in.) to 32 cm (12 in.) long and 2.5 cm (1 in.) wide. It allows your health professional to look into the rectum and the bottom part of the colon, but it does not reach as far into the colon as the flexible sigmoidoscope.

 Go to top of pageGo to top of pageGo to next sectionGo to next section

Author: Maria G. Essig, MS, ELSLast Updated: July 23, 2007
Medical Review: Kathleen Romito, MD - Family Medicine
Anne C. Poinier, MD - Internal Medicine
Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology

© 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

Click here to learn about Healthwise
Click here to learn about Healthwise
Topic Contents
Arrow PointerTest Overview
 Health Tools Click here to view Health Tools.
 Why It Is Done
 How To Prepare
 How It Is Done
 How It Feels
 Risks
 Results
 What Affects the Test
 What To Think About
 References
 Credits