COLONOSCOPY OVERVIEW & Frequently Asked Questions

Colonoscopy is a procedure which enables a physician (usually a gastroenterologist) to directly image and examine the entire colon. It is effective in the diagnosis and/or evaluation of various GI disorders (e.g. colon polyps, colon cancer, diverticulosis, inflammatory bowel disease, bleeding, change in bowel habits, abdominal pain, obstruction and abnormal x-rays or CT scans) as well as in providing therapy (for example, removal of polyps or control of bleeding). It is also used for screening for colon cancer. A key advantage of this technique is that it allows both imaging of abnormal findings and also therapy or removal of these lesions during the same examination. This procedure is particularly helpful for identification and removal of precancerous polyps.

A colonoscope is a flexible and steerable instrument to evaluate the entire colon (large intestine). The large intestine is approximately 3 – 4 feet long. A colonoscope is engineered such that biopsies of suspicious areas can be obtained, and polyps (which may turn into cancer) can be removed.

Yes. Colonoscopy accomplishes this by detecting and removing polyps, and detecting early cancers. Recent data show that both the number of new cases of colon cancer (incidence) and deaths from the disease are decreased when colonoscopy is performed according to established guidelines.

The most common reason patients cite for not getting a colonoscopy is that their doctor did not discuss it with them. The next most common reason is fear or avoidance of the preparation (“prep”), which involves taking a laxative which causes temporary diarrhea for several hours. In addition, many people are simply unaware that they need colon cancer screening.

No, colonoscopy is usually not painful! Almost all colonoscopies can be performed using “intravenous sedation” or “twilight sedation” in which you are very drowsy, but comfortable and still breathing on your own. The most common type of sedation also has a mild amnesiac effect, so most patients do not even remember the procedure! Your doctor can discuss with you the best form of sedation to suit your needs.

Medicare (and most third party payers) will pay for colonoscopy for colon cancer screening, thanks to the hard work of advocacy groups and the efforts of national organizations such as the American College of Gastroenterology (ACG). Regrettably, a recent study showed a low compliance rate for screening (less than 30%) among Medicare patients.

Yes, there are alternative methods to examine the colon, but none are considered more accurate at colon cancer and polyp detection than colonoscopy. They include:

• A flexible sigmoidoscopy
• Computerized tomography (CT), a test that takes pictures of the inside of the colon, can also be done. This is called CT colonography or “virtual colonoscopy.” Like conventional colonoscopy, this test requires a full preparation the day before the exam (liquids and possibly enemas). This test, however, involves radiation exposure which may increase your long term risk of development of cancer.

If any of the above tests suggest the presence of polyps or cancer, a conventional colonoscopy (and a second preparation) will be required. For colon cancer screening, it should be noted that colonoscopy has the highest sensitivity and is the only test that is both diagnostic and therapeutic.

This is an important obstacle in the eyes of many patients to getting a colonoscopy, but it need not be! There are a variety of preparation methods for colonoscopy ranging from liquids (of varying quantity) with or without enemas, to pills, which rid your colon of feces. A clean colon is essential to allow for a careful examination for polyps or other abnormalities. Your doctor can discuss and prescribe the most appropriate preparation method for you, taking into account various factors such as your age, personal preferences, kidney function and physical stamina.

• The most popular preparation used for colonoscopy involves drinking a volume of solution of polyethylene glycol (PEG). This solution causes a diarrhea that effectively rids the colon of its contents. Various fruit flavors are available and patients have several hours to drink it. Usually a patient will have clear liquids the day of the preparation (day before the colonoscopy) and then take half of the prep in the late afternoon or that evening.
• Smaller volumes of solution (e.g. Plenvu®, SuPrep®) or pill preparations (e.g. SuTab®) have also recently become available with similarly good outcomes to PEG for people who dread the thought of large volumes of liquid.

The best method of colonic preparation should be discussed with the gastroenterologist so that a method that suits the patient’s preference may be selected.

Yes, but potential complications are associated with virtually every form of testing done in medicine. Clearly, colonoscopy has been found to be extremely safe when performed by a well trained physician such as a gastroenterologist. Although quite rare, most complications are related to sedation administration (cardiac and respiratory problems); the colon may also become partially torn (perforated) and this may require surgery. Rarely, bleeding from polyp removal or from the procedure itself may require additional treatment such as hospitalization and/or blood transfusions. As one reads about these procedures, the reader should weigh these low risks against the far more frequent complication of developing colon cancer if appropriate testing is NOT done.