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.

Colonoscopy may be done to:

• Check for polyps as a screening test for colorectal cancer.
• Check for the cause of blood in the stool or rectal bleeding.
• Check for the cause of chronic diarrhea.
• Check for the cause of iron deficiency anemia.
• Check the colon after abnormal results from a test, such as a stool test or a CT scan.
• Watch or treat colon problems like inflammatory bowel disease (IBD).
• Check for the cause of long-term, unexplained belly or rectal pain.

This procedure is done in a doctor's office, outpatient surgery center, or hospital. You will get medicine to relieve pain and help you sleep or feel very relaxed. 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.

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

To clean out your colon, you'll do a bowel prep before the test. This means you stop eating solid foods and drink only clear liquids. You can have water, tea and coffee (without milk), 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 or take pills. This causes loose, frequent stools. You will go to the bathroom a lot. Your doctor may have you take part of the prep the evening before and the rest on the day of the test. It's very important to take all of the prep. If you have problems taking it, call your doctor.

Arrange to have someone take you home after the test.

The results of a colonoscopy may be normal or abnormal.

• Normal: The lining of the colon looks smooth and pink. It has a lot of normal folds. No growths, pouches, bleeding, or inflammation are seen.
• Abnormal: Some abnormal findings include hemorrhoids, polyps, cancer, one or more sores (ulcers), pouches in the wall of the colon (diverticulosis), and inflammation. A red, swollen lining of the colon (colitis) may be caused by infection or inflammatory bowel disease (IBD).

If your doctor took a sample of tissue (biopsy) during the procedure, it will be sent to a lab for tests.