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Colonoscopy

Why is this procedure done?

Colonoscopy is done so your doctor can see the inside of your large intestines, also called your colon, and your rectum. It uses a lighted tube called a scope, which has a tiny camera that can be moved through the large intestine. This may be done to:

  • Check for colon cancer or growths called polyps
  • Look for the source of rectal bleeding
  • Find the cause of changes in your bowel movements
  • Find the cause of belly or rectal pain
  • Check results from other tests
  • Check your response to treatment for other diseases
  • Learn about weight loss

What happens before the procedure?

  • Your doctor will ask you about your health history and do an exam. The doctor may order tests for your stool. Talk to the doctor about
    • All the drugs you are taking. Be sure to include all prescription and over-the-counter (OTC) drugs, and herbal supplements. Tell the doctor about any drug allergy. Bring a list of drugs you take with you.
    • Any bleeding problems. Be sure to tell your doctor if you are taking any drugs that may cause bleeding. Some of these are warfarin, rivaroxaban, apixaban, ticagrelor, clopidogrel, ketorolac, ibuprofen, naproxen, or aspirin. Certain vitamins and herbs, such as garlic and fish oil, may also add to the risk for bleeding. You may need to stop these drugs as well. Talk to your doctor about them.
  • The colon needs to be cleaned out before this test. Your doctor will tell you to take drugs that will cause watery loose stools. These may be liquids, pills, or both. You may need to take these the day before and the day of your test.
  • You will be placed on a clear liquid diet the day before the exam and you will need to only have clear liquids until the test is done. Clear liquids include water, sports drinks, broth, soft drinks, and juices, but avoid anything that is red or purple in color. Do not drink alcohol.
  • Your doctor may ask you not to eat or drink any food other than the drugs or liquids that clean out your colon.
  • You will not be allowed to drive after the procedure. Ask a family member or a friend to drive you home and stay with you.

What happens during the procedure?

  • The staff will put an IV in your arm to give you fluids and drugs. You may be given a drug to make you sleepy.
  • You will lie on your side with your knees bent and pulled up toward your chest.
  • The doctor will use a small thin tube, called a scope, with a light and a camera on it. The tube is put into your anus and moved through your rectum and into the large intestine or colon.
  • Small amounts of air are put into your colon. The camera lets your doctor look at the lining of your colon.
  • Your doctor may take small tissue samples and remove small growths.
  • The tube is then taken out.
  • The procedure may take 30 to 45 minutes.

What happens after the procedure?

  • You will go to a recovery area and the staff will watch you closely.
  • You can go home and rest after your procedure.
  • You may feel groggy.
  • You should be able to eat your usual diet after the test.
  • You will have gas and you may have mild cramping. This is normal.
  • A small amount of bleeding may happen during the first few days after your procedure.
  • If tissue was removed, it will be sent to a lab to be checked. Your doctor will tell you the results after a week or two.

What problems could happen?

  • Tear inside your colon
  • Bleeding can happen for a few days afterwards

Where can I learn more?

American Cancer Society

American Society of Clinical Oncology

National Digestive Diseases Information Clearinghouse

Consumer Information Use and Disclaimer

This information is not specific medical advice and does not replace information you receive from your health care provider. This is only a brief summary of general information. It does NOT include all information about conditions, illnesses, injuries, tests, procedures, treatments, therapies, discharge instructions or life-style choices that may apply to you. You must talk with your health care provider for complete information about your health and treatment options. This information should not be used to decide whether or not to accept your health care provider’s advice, instructions or recommendations. Only your health care provider has the knowledge and training to provide advice that is right for you.

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