A colonoscopy is an exam that views the inside of the colon (large intestine) and rectum, using a tool called a colonoscope.
The colonoscope has a small camera attached to a flexible tube that can reach the length of the colon.
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How the Test is Performed
Colonoscopy is done most often in a procedure room at your doctor's office. It can also be done in the outpatient department of a hospital or medical center.
- You will be asked to change out of your street clothes and wear a hospital gown for the procedure.
- You are likely given medicine into a vein (IV) to help you relax. You should not feel any pain. You may be awake during the test and may even be able to speak. You will probably not remember anything.
- You lie on your left side with your knees drawn up toward your chest.
- The colonoscope is gently inserted through the anus. It is carefully moved into the beginning of the large intestine. The scope is slowly advanced as far as the lowest part of the small intestine.
- Air is inserted through the scope to provide a better view. Suction may be used to remove a fluid or stool.
- The doctor gets a better view as the scope is moved back out. So, a more careful exam is done while the scope is being pulled back.
- Tissue samples (biopsy) or polyps may be removed using tiny tools inserted through the scope. Photos may be taken using the camera at the end of the scope. If needed, procedures, such as laser therapy, are also done.