Virtual colonoscopy, also called CT colonography, is an alternative to colonoscopy, producing 2-D and 3-D images of the colon that are displayed on a screen. It uses a CT scanner to produce hundreds of cross-sectional images that provide a detailed view of the colon’s interior, from the lower end of the small intestine to the rectum, without needing to insert a colonoscope. This procedure is suited for patients who are frail, elderly or aren’t able to undergo a colonoscopy for other reasons.
Properly performed, a virtual colonoscopy is as accurate in detecting polyps as a traditional colonoscopy. If polyps are found during the exam, a subsequent colonoscopy may be needed to remove these. Both procedures require a bowel preparation to clear out stool and examine the inside lining of the colon.