CT colonography is a radiology test that looks at the colon (large intestine). It is one of many options for colon cancer screening.
This test is used to look for polyps or cancers of the colon.
CT colonography is safe. It can be used if you are too sick to have other forms of colon cancer screening.
In some cases, a contrast material is used. One complication may be an allergic reaction to the contrast.
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.
You will be able to leave after the test is done. You can resume your normal diet and activities.
An specialist will review the images. If something abnormal is seen, your doctor may suggest a colonoscopy.
American College of Gastroenterology
National Institute of Diabetes and Digestive and Kidney Diseases
Canadian Association of Gastroenterology
Canadian Cancer Society
CT colonography. Radiology Info—American College of Radiology website. Available at: https://www.radiologyinfo.org/en/info.cfm?pg=ct_colo. Updated March 17, 2016. Accessed October 3, 2017.
Fletcher RH. Colorectal cancer screening on stronger footing. NEJM. 2008;359(12):1285-1287.
Johnson CD, Chen MH, Toledano AY, 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. 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.
Last reviewed September 2017 by EBSCO Medical Review Board Daus Mahnke, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.