Learning About Colonoscopy

What is a colonoscopy?

A colonoscopy is a test (also called a procedure) that lets a doctor look inside your large intestine. The doctor uses a thin, lighted tube called a colonoscope. The doctor uses it to look for small growths called polyps, colon or rectal cancer (colorectal cancer), or other problems like bleeding.

During the procedure, the doctor can take samples of tissue. The samples can then be checked for cancer or other conditions. The doctor can also take out polyps.

How is a colonoscopy done?

This procedure is done in a doctor's office or a clinic or hospital. You will get medicine to help you relax and not feel pain. Some people find that they don't remember having the test because of the medicine.

The doctor gently moves the colonoscope, or scope, through the colon. The scope is also a small video camera. It lets the doctor see the colon and take pictures.

How do you prepare for the procedure?

You need to clean out your colon before the procedure so the doctor can see your colon. This depends on which "colon prep" your doctor recommends.

To clean out your colon, you'll do a "colon prep" before the test. This means you stop eating solid foods and drink only clear liquids. You can have water, tea, coffee, clear juices, clear broths, flavored ice pops, and gelatin (such as Jell-O). Do not drink anything red or purple.

The day or night before the procedure, you drink a large amount of a special liquid. This causes loose, frequent stools. You will go to the bathroom a lot. Your doctor may have you drink part of the liquid the evening before and the rest on the day of the test. It's very important to drink all of the liquid. If you have problems drinking it, call your doctor.

Arrange to have someone take you home after the test.

What can you expect after a colonoscopy?

Your doctor will tell you when you can eat and do your usual activities.

Drink a lot of fluid after the test to replace the fluids you may have lost during the colon prep. But don't drink alcohol.

Your doctor will talk to you about when you'll need your next colonoscopy. The results of your test and your risk for colorectal cancer will help your doctor decide how often you need to be checked.

After the test, you may be bloated or have gas pains. You may need to pass gas. If a biopsy was done or a polyp was removed, you may have streaks of blood in your stool (feces) for a few days. Check with your doctor to see when it is safe to take aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) again.

Problems such as heavy rectal bleeding may not occur until several weeks after the test. This isn't common. But it can happen after polyps are removed.