The best test currently available to screen for colorectal cancer is a colonoscopy. It is usually recommended
starting at age 50 and repeated every 10 years. If someone has an increased risk for the disease, or has had
previous treatment for colon polyps or colorectal cancer, the test may be done more often.
An accurate colonoscopy requires a clean colon and rectum. Preparation begins the day before your scheduled
procedure. You will take a physician-prescribed colon-cleansing agent and your diet will be restricted. The
strong laxative helps clear out any food in the lower digestive tract. Both liquid and tablet formulations are
available. Typically, when a liquid is prescribed, the amount can vary from three ounces to a gallon. When pills
are prescribed, as many as 40 pills may be taken, usually 4 pills at a time every 15 minutes.
The colonoscopy is performed on an outpatient basis and generally takes less than 60 minutes to complete. Just
before undergoing the colonoscopy, you will most likely receive a sedating agent to help you to relax and to
minimize any potential discomfort.
During a colonoscopy exam, the physician explores the full length of the colon to detect pre-cancerous polyps
and cancerous growths.
While you are lying on your side, your physician will gently insert a narrow colonoscope into the rectum and
slowly up through the entire colon. Using the colonoscope, your physician can view the inside lining of the
entire rectum and entire colon on a TV monitor.
If your physician notes any abnormal tissue or polyps, he/she may use the colonoscope to take a sample, or
biopsy, for analysis. After the procedure is complete, you will be able to recover in the recovery room. If
you received a sedating agent for the procedure, you will need a family member or friend to pick you up and
take you home. This is an invasive procedure and does carry some small risk such as infection, bleeding or
perforation of the colon.
