Who should have a colonoscopy?

Although it is preventable, colorectal cancer is still the third-most common cancer diagnosed in the United States. In 2007, 142,672 people were diagnosed with it. Regular screening, beginning at age 50 through to age 75, is the key to prevention. Your doctor can advise you how often to get a colonoscopy.

If there is a history of colorectal cancer in your family, you have a higher risk of developing it and should begin screening at a younger age, and you may need to be tested more frequently.

What is a colonoscopy?

A colonoscopy enables the physician to examine the lining of the colon (large intestine or large bowel) for abnormalities. The colonoscope is a four-foot-long, flexible tube with a camera and a source of light at its tip. While the patient is under sedation, 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.

Does it hurt?

No. The procedure, which can take as little as 15 minutes to an hour or so, does not hurt. Patients are given medicine to sleep through the test, so they don't feel anything. When air is pumped into the colon (to keep it open, so that the doctor can get the best and clearest picture), there may be some mild discomfort, but it should not be painful.

What bowel preparation is needed for a colonoscopy?

The colon has to be completely clean. In general, patients drink a large volume of a special cleansing solution or undergo several days of a clear liquid diet and laxatives. Patients have to follow the instructions exactly as prescribed or the procedure may not work properly and have to be repeated.

What should I expect during a colonoscopy?

Before a colonoscopy, the patient's heart rhythms and blood pressure are monitored. Sedatives are usually given through an intravenous line so that patients become sleepy and relaxed. If needed, patients may receive additional doses of medication during the procedure. During the procedure, patients lie on their left side or back as the colonoscope is slowly advanced. Once the tip of the colon is reached, the colonoscope is slowly withdrawn, and the lining of the colon is carefully examined.

How long does it take?

A colonoscopy usually takes 15 to 60 minutes. If the entire colon, for some reason, cannot be visualized, the physician may decide to try a colonoscopy again at a later date with or without a different bowel preparation or may decide to order an X-ray or CT of the colon.

What should I expect after the colonoscopy?

Patients are kept under observation for an hour or two after their colonoscopy, until the effects of medications wear off. If patients have been given sedatives before or during colonoscopy, they can't drive, even if they feel alert.

When will I get the results?

After the procedure, your doctor will discuss his or her findings. However, a definitive diagnosis may take several days longer, as a microscopic analysis of any biopsy specimens may be necessary.

What if an abnormality is found?

If your doctor thinks an area of the bowel needs to be evaluated in greater detail, a biopsy will be taken and analyzed. If polyps are found, they are generally removed if it is safe to do so. Generally, these procedures are not painful.