Colonoscopy is a very useful tool in the evaluation and treatment of diseases of the colon and rectum. It is a minimally invasive procedure in which the entire lining of the colon can be examined by directly looking at the lining. Biopsies (samples of the lining) can be taken during colonoscopy. Polyps (small growths in the lining of the colon) can also be removed during colonoscopy. Removal of polyps may help prevent colon cancer before it develops.

Colonoscopy is performed in a specially equipped room, usually in an endoscopy suite or lab. An intravenous line (IV) is usually placed before the procedure starts so that medications and fluids can be given to the patient. The procedure begins after sedatives (sleeping medicines, like Valium) are given. Enough medicine is given to make the patient sleepy, but not unconscious.

The procedure usually begins with the patient lying on his/her left side. The colonoscope is a long flexible tube with a light and video camera at the tip, and wheels for steering the tip at the other end. It is inserted through the anal opening and advanced to the beginning of the colon. This is done under direct vision, with the doctor watching the scope advance through the colon on a monitor. (The patient can also watch the procedure, if he/she desires and is not too sleepy.)

During this insertion phase, the patient may experience cramping, especially as the scope is being pushed around corners. The assistant will often need to push on the patient’s abdomen to help the scope move forward, and the patient may be asked to lie in different positions. Careful inspection of the lining is made during the removal of the scope, and air is blown into the colon to help separate the walls and allow the doctor to see better. Any abnormalities can be biopsied (sampled), and small growths (polyps) can be removed (polypectomy).

There are several things to do to get ready for a colonoscopy.

1. It is important that the patient be accompanied to the procedure by a friend or family member. The sedation (sleeping medicine) given during the colonoscopy makes it unsafe for the patient to drive or travel alone. It is best to make arrangements for a friend or family member to escort the patient home after the procedure.
2. Diet restriction the day before the procedure (clear liquids) and medicine to cause diarrhea (bowel prep) are necessary to clean the colon. This is important so that the lining of the colon can be seen clearly and the colonoscope inserted fully to the beginning of the colon.
3. Bleeding is a concern after removal of a polyp. Therefore, it is important to avoid any medicines that thin the blood and prevent blood from clotting for one week before the colonoscopy. These medicines include all over-the-counter pain medications and fever reducing cold remedies, except those that only use acetaminophen (Tylenol). Additionally, medicines used for poor circulation and stroke prevention, or for artificial heart valves, such as Coumadin and Plavix should also be stopped. Finally, there are some herbal medicines that thin the blood, such as Gingko Biloba, that should also be avoided. It is important to discuss these medicines with your doctor that prescribed them, or the doctor that