Colonoscopy

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What is colonoscopy?

Colonoscopy is a procedure that enables an examiner (usually a gastroenterologist) to evaluate the inside of the colon (large intestine or large bowel). The colonoscope is a four foot long, flexible tube about the thickness of a finger with a camera and a source of light at its tip. The tip of the colonoscope is inserted into the anus and then is advanced slowly, under visual control, into the rectum and through the colon usually as far as the cecum, which is the first part of the colon.

Why is colonoscopy done?

Colonoscopy may be done for a variety of reasons. Most often it is done to investigate the cause of blood in the stool, abdominal pain, diarrhea, a change in bowel habit, or an abnormality found on colonic X-rays or a computerized axial tomography (CT) scan. Individuals with a previous history of polyps or colon cancer and certain individuals with a family history of some types of non-colonic cancers or colonic problems that may be associated with colon cancer (such as ulcerative colitis and colonic polyps) may be advised to have periodic colonoscopies because their risks are greater for polyps or colon cancer. How often should one undergo colonoscopy depends on the degree of the risks and the abnormalities found at previous colonoscopies. It has been recommended that even healthy people at normal risk for colon cancer should undergo colonoscopy at age 50 and every 10 years thereafter, for the purpose of removing colonic polyps before they become cancerous.

What bowel preparation is needed for colonoscopy?

If the procedure is to be complete and accurate, the colon must be completely cleaned, and there are several colonoscopy preparations . Patients are given detailed instructions about the cleansing preparation. In general, this consists of drinking a large volume of a special cleansing solution or several days of a clear liquid diet and laxatives or enemas prior to the examination. These instructions should be followed exactly as prescribed or the procedure may be unsatisfactory (visualization of the lining of the colon may be obscured by residual stool), and it may have to be repeated, or a less accurate alternative test may be performed in its place.


Patient Comments

Viewers share their comments

Colonoscopy - Describe Your Experience Question: Please describe your experience with a Colonoscopy.
Colonoscopy - Preparation Question: What steps did you take in preparation for your colonoscopy?

Colonoscopy and Colon Polyps

Viewer Question: I just had a colonoscopy and they found two non-cancerous colon polyps and one non-cancerous lipoma (no previous polyps prior), when should I have my next colonoscopy?

Doctor's Response: Lipomas (benign tumors consisting of fat) are benign, that is, they are not cancerous. If the pathologist (the doctor who examines the polyp) is confident that the polyp is a lipoma, no further tests or surveillance will be necessary.

When to perform the next colonoscopy after removal of two non-cancerous, non-lipomatous polyps depends on several issues:

  1. The size of the polyps.
  2. The Completeness of the excision.
  3. The degree of atypia in the cells that make up the polyps. (Atypia is a term pathologists use to describe cells that appear to be in the process of turning cancerous.)
  4. The quality of the colon preparation and visualization.


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