Virtual Colonoscopy


Virtual colonoscopy (VC) is an imaging or x-ray test that looks for cancer, polyps, or other disease in the large intestine (colon).

How the Test is Performed

A virtual colonoscopy is different from a regular colonoscopy, in which a long, lighted tool called a colonoscope is inserted into the rectum and large intestine. No sedatives are needed and no scope is used.
  • X-rays create images of your colon.
  • Pictures are taken while you lie on your stomach and back.
  • You may be asked to hold your breath briefly while each picture is taken.
A computer combines all the images to form three-dimensional pictures of the colon, which are viewed on a video monitor.

How to Prepare for the Test 

 Everyone undergoing any type of colonoscopy must completely empty their bowels before the exam. This may be done using laxatives combined with a liquid diet the day before the test. The bowel must be completely emptied until no solid matter remains.

Drink plenty of clear liquids, such as apple juice and chicken broth, to avoid dehydration.

Make sure you tell your health care provider about any medications you are taking. You will be told which you can take, and which you should temporarily stop.

Why the Test is Performed

 Virtual colonoscopy may be performed to:
  • Follow-up on colon cancer or polyps
  • Look for the cause of: Abdominal pain, changes in bowel movements, or weight loss
  • Anemia due to low iron
  • Blood in the stool or black, tarry stools
  • Screen for cancer of the colon or rectum (should be done every 5 years)

Other times, a virtual colonoscopy is done if your doctor was not able to move the flexible tube all the way through the colon during a conventional colonoscopy. (Incomplete Colonoscopy)

Burt RW, Barthel JS, Dunn KB, David Ds, Drelichman E, Ford JM, et al. NCCN clinical practice guidelines in oncology. Colorectal cancer screening. J Natl Compr Canc Netw . 2010;8:8-61.
Bresalier RS. Colorectal cancer. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease . 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 123.
Share by: