In a colonoscopy, the entire length of your large intestine (colon) is examined, and polyps are removed and cancer can be found. If your first colonoscopy doesn’t find a problem, you may not need another one for 10 years if you are at average risk.
What to expect
For the test to be effective, you have to empty your colon completely beforehand. For the day before, you’ll eat no food and drink only clear liquids. You’ll take a laxative (in liquid or pill form) and, if needed, give yourself an enema. On the day of the test, you’ll be given sedation meds through a needle in your arm (IV) to relax you. While you’re lying on your side, your doctor inserts a long, flexible tube containing a camera through your anus and into your rectum and colon. This allows your doctor to see inside your large intestine. Polyps can be removed using tools inserted through the tube. Your doctor can also collect tissue samples (biopsy) to check for cancer. The whole procedure takes about 30 minutes. Because you’ve been sedated, you won’t be able to drive, so you'll need to arrange for a ride home.
If any of the following screening tests detect abnormalities, your doctor may recommend you have a colonoscopy.