Colonoscopy is a test to view the inside of your lower digestive tract (colon and rectum). Sometimes it can show the last part of the small intestine (ileum). During the test, small pieces of tissue may be removed for testing. This is called a biopsy. Small growths, such as polyps, may be removed.

The test is done:

• To look for colon cancer or polyps.
• To help find the source of belly (abdominal) pain or bleeding.
• To help find the cause of changes in bowel habits.

It may be needed every 5 to 10 years. Or it may be needed more often. This depends on factors, such as your:

• Age.
• Health history.
• Family health history.
• Abdominal or bowel symptoms and concerns.
• Results from past testing.

These include:

• Bleeding.
• A hole (puncture) or tear in the colon.
• Risks from or reaction to sedation medicine (anesthesia).
• A cancer sore (lesion) not being seen or fully removed during the test or from past testing or procedures.

To prepare for the test:

• Talk with your doctor about the risks of the test (see below). You can also ask about other options.
• Tell your doctor what medicines you take. This includes over-the-counter and prescription medicines. It also includes vitamins, herbs, and supplements. You will likely be advised to stop taking any blood-thinning medicines before the test.
• Tell your doctor what health conditions and allergies you have.
• Make sure your rectum and colon are empty for the test. This is done by following the diet and bowel prep instructions exactly. If you don't follow the directions, the test may need to be rescheduled.

The test is often done in the hospital on an outpatient basis. Or it's done at an outpatient clinic. Outpatient means you go home the same day. The procedure usually takes about 30 minutes. During that time:

• You're given relaxing (sedating) medicine through an I.V. (intravenous) line. You may be drowsy. Or you may fall asleep.
• The doctor will first do a physical exam. This is done to check for anal and rectal problems.
• Then the anus is lubricated and the scope is inserted.
• You may feel like you need to have a bowel movement if you're awake. You may feel pressure as air is pumped into the colon. It's okay to pass gas during the procedure.
• Biopsy, polyp removal, or other treatments may be done during the test.

You may pass gas after the test. This can help you get rid of gas and prevent bloating or discomfort. Your doctor may talk with you right away about the test results. Or you may need to schedule a follow-up visit to talk about the results.

You will need to have someone drive you home after the procedure.

You can go back to your normal eating and other activities after the test, if you are able to. You may be tired from the sedation and need to rest for the rest of the day. Ask your doctor when you can take your regular medicines again. This is especially important if you are on any medicines that thin your blood. Some doctors may want you to stop taking blood thinners for a few days after the test.

When your doctor says it's okay, restart your exercise program with walking. Then slowly start to walk and exercise more if you are able to.

Drink plenty of water after your procedure. But stay away from any alcohol for 8 to 24 hours.

Contact your doctor right away if you have:

• Severe belly (abdominal) pain.
• A bloated or firm belly.
• A fever of 100.4°F (38°C) or higher, or as advised by your doctor.
• Rectal bleeding or bloody bowel movements.
• Nausea or vomiting.
• Weakness or dizziness.