Munson Health
CT Colonography

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by Mahnke D

(Computed Tomography Colonography; Virtual Colonoscopy)


Reasons for Test

This test is used to look for polyps or cancers of the colon.
Colon Polyps
Nucleus Image
Copyright © Nucleus Medical Media, Inc.

What to Expect

Description of the Test

You will be positioned on your back on a movable x-ray table. Just before the test, a small tube will be inserted into your rectum. Air will be gently pumped through this tube. The table will move slowly though the donut-shaped CT scanner. While this is happening, you will need to lie very still. You will be asked to hold your breath during the scan. The scanning test will then be repeated with you lying on your stomach.

After Test

You will be able to leave after the test is done. You can resume your normal diet and activities.

How Long Will It Take?

30-40 minutes

Will It Hurt?

You may feel cramping and bloating. You may feel the urge to have a bowel movement.


An expert will review the images. If something abnormal is seen, your doctor may suggest a colonoscopy .


American College of Gastroenterology

National Digestive Diseases Information Clearinghouse



Canadian Association of Gastroenterology

Canadian Cancer Society



CT colonography.—American College of Radiology website. Available at: . Updated May 16, 2014. Accessed September 17, 2014.

Fletcher RH. Colorectal cancer screening on stronger footing. NEJM. 2008;359:1285-1287.

Johnson CD, et al. Accuracy of CT Colonography for Detection of Large Adenomas and Cancers. NEJM. 2008;359(12): 1207-1217.

Mulhall P, Veerappan GR, Jackson JL, et al. Meta-analysis: computed tomographic colonography. Ann Intern Med. 2005;142(8):635-650.

Yee J. Screening CT Colonography. Radiol Clin North Am. 2004;42(4):757-766.


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