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.
What to Expect
Prior to Test
Do not eat for 8-12 hours prior to the test.
A bowel cleansing will be done with a laxative. The goal of the cleansing is to rid your colon of all stool. The laxative will cause you to have many bowel movements over several hours.
If you have
diabetes, talk to your doctor about adjusting your medications.
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.
You will be able to leave after the test is done. You can resume your normal diet and activities.
How Long Will It Take?
Will It Hurt?
You may feel cramping and bloating. You may feel the urge to have a bowel movement.
An specialist will review the images. If something abnormal is seen, your doctor may suggest a
Call Your Doctor
It is important to monitor your recovery. Alert your doctor to any problems. If any of the following occur, call your doctor:
If you think you have an emergency, call for emergency medical services right away.
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 2018 by
EBSCO Medical Review Board
Daus Mahnke, MD
Last Updated: 9/17/2014
EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.
This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.
To send comments or feedback to our Editorial Team regarding the content please email us at email@example.com. Our Health Library Support team will respond to your email request within 2 business days.