McKay-Dee Hospital

(801) 387-2800Map4401 Harrison Blvd.Ogden, UT 84403

back to Health Education

What is a Colonoscopy?

Colonoscopy is a procedure that uses a device called a colonoscope to look at the inside of your colon and rectum. The colonoscope is a long, flexible tube with a tiny video camera at the end. The camera sends images to a monitor, allowing your doctor to see a variety of problems.

Why do I need it? Colonoscopy

For people at risk, colonoscopy is the best test to screen for colon cancer, pre-cancerous growths, and polyps. If an abnormal growth or polyp is found, the doctor can remove it, take a biopsy, or recommend surgical removal later. Detecting and removing growths may prevent cancer from developing. 

A colonoscopy also helps your doctor see other problems that may be causing abdominal pain, weight loss, or changes in bowel habits. This includes ulcers, narrowed areas, inflammation, or bleeding.

Potential Benefits

  • Colonoscopy is the best test for detecting pre-cancerous polyps and cancer. 
  • The doctor can often remove polyps, perform biopsies, and treat problems during the procedure itself.

Potential Risks

  • Some people have cramps and abdominal swelling. This is caused by the air used to inflate the colon, and passes shortly after the procedure. 
  • If your doctor takes a biopsy, you may see small amounts of blood in your stool after the procedure. If there’s a lot of blood, you may need another colonoscopy, or possibly surgery. 
  • There is a slight risk (1 in 3,000) of perforating the colon. This may cause bleeding or infection. If this occurs, you may need immediate surgery to repair the injury. 
  • If the colon and rectum were difficult to examine or not completely empty, the procedure may not detect some problems. 
  • As with any medicine, there’s a slight chance you may have a reaction to the sedative.


  • Diet changes and/or medication—these give only temporary relief. 
  • Traditional surgery with one larger incision—this might be necessary if you have scar tissue, have had previous abdominal surgery, or if there are complications during the surgery.

What happens before?

In most cases, you’ll be given a sedative to help you relax. This is given through an intravenous line (IV) inserted into a vein in your arm.

What happens during?

  • You’ll lie on your left side while the doctor inserts the colonoscope into your rectum.
  • A camera at the tip of the colonoscope sends images to a monitor so the doctor can look closely at the inside lining of your colon. The scope puts air into your colon to infl ate it and give the doctor a better view.
  • Your doctor can also insert instruments through the colonoscope to remove polyps, take tissue samples, inject solutions, destroy abnormal tissue, or help widen openings.

What happens after?

  • You’ll stay at the facility until you’re partially recovered from the sedative. This usually takes about an hour. However, the sedative can take several hours (up to a full day) to wear off completely. Since you’ll still be sleepy, you’ll need to arrange for a responsible person to drive you home.
  • You may feel bloated or have gas for a few hours. You may also see a small amount of blood with your first stool.
  • Depending on the quality and findings of this exam, you may need follow-up procedures. Talk with your doctor.

For your convenience you may download and print this Colonoscopy Fact Sheet.

back to Health Education

The content presented here is for your information only. It is not a substitute for professional medical advice, and it should not be used to diagnose or treat a health problem or disease. Please consult your healthcare provider if you have any questions or concerns. More health information is available at

Copyright © , Intermountain Healthcare, All rights reserved.