A virtual colonoscopy uses x-rays and computers to produce two- and three-dimensional images of the colon (large intestine) from the lowest part, the rectum, all the way to the lower end of the small intestine and display them on a screen. The procedure is used to diagnose colon and bowel disease, including polyps, diverticulosis, and cancer. Virtual colonoscopies can be performed with computed tomography (CT), sometimes called a CAT scan, or with magnetic resonance imaging (MRI).
What happens during a virtual colonoscopy?
A virtual colonoscopy takes place in the radiology department of a hospital or medical center. The examination takes about 10 minutes and does not require sedatives.
The doctor will ask you to lie on your back on a table. A thin tube will be inserted into your rectum, and air will be pumped through the tube to inflate the colon for better viewing.
The table moves through the scanner to produce a series of two-dimensional cross-sections along the length of the colon. A computer program puts these images together to create a three-dimensional picture that can be viewed on the video screen. You will be asked to hold your breath during the scan to avoid distortion on the images.
The scanning procedure is then repeated with you lying on your stomach. After the examination, the information from the scanner must be processed to create the computer picture or image of your colon. A radiologist evaluates the results to identify any abnormalities.
You may resume normal activity after the procedure, although your doctor may ask you to wait while the test results are analyzed. If abnormalities are found and you need conventional colonoscopy, it may be performed the same day.
A virtual colonoscopy is more comfortable than conventional colonoscopy for some people because it does not use a colonoscope. As a result, no sedation is needed, and you can go home after the procedure without the aid of another person. VC provides clearer, more detailed images than a conventional x-ray using a barium enema, sometimes called a lower gastrointestinal (GI) series. It also takes less time than either a conventional colonoscopy or a lower GI series.
The main disadvantage of a virtual colonoscopy is that the doctor cannot take tissue samples or remove polyps, so a conventional colonoscopy must be performed if abnormalities are found. Also, the procedure does not show as much detail as a conventional colonoscopy, so polyps smaller than 10 millimeters in diameter may not show up on the images.
How do you prepare for a virtual colonoscopy?
Preparations for a virtual colonoscopy vary, but you will usually be asked to take laxatives or other oral agents at home the day before the procedure to clear out your colon. You may also be asked to use a suppository to cleanse your rectum.
What results will I have if I am suffering from IBS?
No abnormalities will be found if you are suffering from IBS alone.
virtual colonoscopy experiences
The tale of...Teresa
Well as you may imagine the worst part was taking the Picolax. I haven't moved so fast in years! The procedure was done on a CT scanner (I had a whole body scan at the same time). Glad I had read the description above about the tube etc. That was the most uncomfortable part, being blown up like a balloon. However, it was not what I would call painful, just not pleasant. It was over quite quickly and as soon as the gas was turned off I started to feel better.
I won't have any results for a few days but I am really pleased with the procedure. My father died of bowel cancer and I had been putting off having a standard colonoscopy for the last three years.