by Albert Aunchman

Created on: April 24, 2008   Last Updated: April 29, 2008

What is a colonoscopy?

A colonoscopy is a procedure that allows a doctor to visually examine the inner lining of your large intestine. A colonoscope, a long, flexible tube about the thickness of a finger, is inserted into your rectum. A tiny video camera allows the doctor to view the inside of your colon on a monitor. Small puffs of air enable him to clearly examine the lining of your large intestine to check for abnormalities such as polyps, ulcers, or other suspicious tissue that could become cancerous. In the event that a polyp, or abnormal tissue is found, your doctor can choose to remove it, or destroy it with cautery. He does this by inserting tiny tools into the hollow colonoscope.

Preparing for the Exam

Before going for your colonoscopy, you will need to clean out your colon. Prep kits can be purchased at any pharmacy, and the directions are clear and easy to follow. The cleaner your bowel is on the day of the exam, the better the chances of a good-quality exam. For many people, the preparation process is the most difficult part of the entire procedure.

The Day of the Exam

Colonoscopies are usually done at clinics, or hospitals. A gastroenterologist usually performs them. The entire process, which can take from 30 to 45 minutes, is usually done under "conscious sedation", a mild form of anesthesia that allows you to relax. In fact most patients have no recollection of the procedure upon awakening. You will need to be driven home since you will be slightly drowsy for a little while.

Though you may get immediate feedback, your doctor will still want to see you in a few weeks to go over the exam in detail. If nothing was amiss and your risk factors are low, you may not have to have another colonoscopy for ten years. If polyps were removed or the quality of the exam was compromised by inadequate prep or other factors, your doctor may want to repeat the test sooner.

A colonoscopy has a low risk of side effects. Some people may have gas for a few hours after the exam, or pass tiny amounts of blood in their stool, but this is not the norm and usually passes within a few days.

Virtual colonoscopy, where a CT scan is used to take two- and three-dimensional pictures of the colon, is another option. This is less uncomfortable for people with an average risk for colon cancer. If a problem is found, however, you may need a standard colonoscopy so a biopsy can be done. Virtual colonoscopy may fail to identify small polyps. Other factors to consider before choosing a virtual colonoscopy are that it requires the same preparation, and is not covered by all health plans.

Colonoscopy is very reliable, safe, and painless. It would be a shame to have a cancer advance to the stage of being difficult to treat, when a colonoscopy could have detected it in its early stages.

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