Colonoscopy prep requires you to empty your colon completely. Starting about 12 hours before your exam, you’ll be required to avoid solid foods and colored liquids. You may also need to take a laxative and possibly perform an enema.
On the day of your colonoscopy appointment, you’ll be given sedation medication through an IV so you feel relaxed while your doctor examines the entire length of your large intestine (colon).
During the colonoscopy, you’ll lie on your side on an examining table with your knees bent. Your doctor will insert a narrow scope (colonoscope) with a tiny camera on the end through your anus to examine your rectum and your large intestine. They will look for irregularities, such as colon polyps – fleshy growths in your colon’s lining that can lead to cancer. If any polyps are found, they can be removed via a colonic polypectomy using tools inserted through the tube. Your doctor can also collect tissue samples during the procedure. Any abnormal tissue can be biopsied to test for colorectal cancer.
During a virtual colonoscopy (CT colonography), your doctor will perform CT scans to produce pictures of your colon. You’ll lie on your back and your stomach so your doctor can get images from different angles. These scans are then reviewed to check for colon polyps and other abnormalities.
Both a colonoscopy and a virtual colonoscopy each take about 30 minutes to complete. Recovery time is usually about an hour.
After a colonoscopy, it can take up to an hour for the sedative to begin to wear off, and up to a day for the effects of the sedative to disappear completely. Because of this, you won’t be able to drive or work after the colonoscopy, and will need to arrange for a ride home. You should be able to return to normal activity the following day.
If you're 50 or older, your doctor will probably want you to have colonoscopies regularly – this is the most common colonoscopy age to begin getting screened.
If you're younger, and any of the following colon cancer risk factors apply, your doctor may suggest you start early colonoscopy screenings:
Ask your doctor when you should start and how often you should have a colonoscopy.
Colon cancer grows slowly and doesn't always cause symptoms in the early stages. But as it progresses, it can cause:
If you notice any of these warning signs, call your colonoscopy doctor (gastroenterologist).