(VC, CT Colonography)
Pronounced: virtual koh-luh-NAHS-kuh-pee
A virtual colonoscopy is a procedure in which x-rays and computers produce two and three dimensional images of the entire large intestine. The procedure is used to diagnose colon and bowel disease, diverticulitis , and colon polyps that could lead to cancer .
Parts of the Body Involved
Virtual colonoscopy creates an image of the colon (large intestine) only.
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Reasons for Procedure
Virtual colonoscopy is used to diagnose the possibility of colon cancer, diverticulitis, polyps in the colon, and diseases of the bowel and colon. The procedure is conducted preventively (without symptoms) and also to diagnose problems in patients who are experiencing symptoms.
Risk Factors for Complications During the Procedure
Pregnant woman should not undergo virtual colonoscopy because the radiation emitted during the imaging procedure can cause damage to a fetus.
What to Expect
Prior to Procedure
Before virtual colonoscopy, patients are required to:
- Take a laxative to cleanse the bowels the day before the procedure.
- Use a suppository to cleanse the rectum of any feces.
- For 24 hours prior to the procedure, avoid eating solid foods.
No anesthesia is administered before or during a virtual colonoscopy.
Description of the Procedure
During the procedure:
- You lie on a table on your back.
- A small, thin, flexible tube is inserted into the rectum, through which air is blown into the colon. Inflating the colon with air allows a more accurate view.
- You must hold your breath during the procedure to prevent blurring or distortion of images.
- The table moves through the imaging device, which captures two-dimensional, cross-sectional views of the entire length of the colon. The images are displayed on a screen like a video.
- You then flip over onto your stomach, and the procedure is repeated.
Once the diagnostic imaging is complete, the images stored by the scanner are converted into computer images. These images are analyzed by a radiologist to identify any abnormalities captured by the scan.
How Long Will It Take?
The procedure takes approximately 10-20 minutes.
Will It Hurt?
When air is forced into the colon, some patients experience abdominal cramping or minor discomfort.
Virtual colonoscopy is a very safe procedure, with complications and side effects extremely rare. Some possible complications include:
- The air that causes the colon to expand can cause the colon to perforate or rupture.
- Because you are exposed to radiation during the procedure, there is a very slight risk of developing cancer related to the radiation exposure.
- Pregnant women should avoid CT scans because they may be harmful to the fetus.
Average Hospital Stay
Virtual colonoscopy is an outpatient procedure, so no hospital stay is required.
Patients may resume normal activities as soon as the procedure is completed. Patients may eat, drink, and resume physical activity immediately following the procedure.
National Digestive Diseases Information Clearinghouse
Radiological Society of North America
Brigham and Women's Hospital
British Columbia Ministry of Health
Colon cancer: virtual colonoscopy. The Mayo Clinic website. Available at: http://www.mayoclinic.com/health/virtual-colonoscopy/CO00019 . Accessed May 28, 2007.
Jani S. Virtual colonoscopy: are we there yet? National Cancer Institute website. Benchmarks. 2004;4(2). Available at: http://www.cancer.gov/newscenter/benchmarks-vol4-issue2/page1 . Accessed May 28, 2007.
Senagore A. Computed tomographic virtual colonoscopy. American Society of Colon & Rectal Surgeons website. Available at: http://www.fascrs.org/displaycommon.cfm?an=1&subarticlenbr=232 . Accessed May 28, 2007.
Last reviewed August 2007 by 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.
Copyright © 2007 EBSCO Publishing All rights reserved.