advertisement



Q & A Library


Print this page | Sign up for free e-bulletins
 | Bookmark This Page

Q
New Colon Cancer Test?
What are the pros and cons of a virtual colonoscopy?
A
Answer (Published 5/18/2004)

A "virtual colonoscopy" relies on images generated by CT (computerized tomography) or MRI (magnetic resonance imaging) to reveal abnormal growths in the colon. It is an alternative to traditional colonoscopy during which doctors examine the length of the colon with a colonoscope, a long, thin tube equipped with a tiny camera at the end to transmit pictures as the device is maneuvered inside the colon.

Related Weil Products
Dr. Weil's Vitamin Advisor for Men's Health - Many health issues men face, such as prostate cancer and erectile dysfunction, may be addressed with proper lifestyle and nutritional supplementation. Find out what is recommended for your health - get a free, personalized vitamin & supplement recommendation from Dr. Weil's Vitamin Advisor.

Until recently, we had no good evidence showing that virtual colonoscopy is as accurate as the conventional method. But results of a study published in the Dec. 4, 2003, issue of the New England Journal of Medicine suggest that virtual colonoscopy works as well - if not better than - the older procedure. Researchers at the National Naval Medical Center (NNMC) reported that virtual colonoscopy found polyps that were at least 10 millimeters in diameter 93.8 percent of the time, and detected growths of at least 8 millimeters in diameter 93.9 percent of the time. By comparison, conventional colonoscopy found polyps that were at least 10 millimeters 87.5 percent of the time and growths of at least 8 millimeters only 91.5 percent of the time. The study included more than 1,200 people between 40 and 79 with no symptoms of colorectal cancer.

From a patient's point of view, the advantages of virtual colonoscopy over the conventional procedure are that it does not require sedation and takes only 10 minutes, compared to 30 to 60 minutes for a conventional colonoscopy. It also avoids the small but real risk of perforation of the colon with the older procedure. With the virtual method, you lay flat on a table and a small catheter is inserted into the rectum. An inert gas is pumped into the colon to inflate it for better viewing. You are required to hold your breath while the table moves through the scanner. The procedure is then repeated with you lying on your stomach. The minor discomfort caused by distension of the colon is minimal compared to having an instrument put inside you.

The disadvantages are that should polyps or growths be found during virtual colonoscopy, a conventional colonoscopy must be performed to remove them, which mean that patients must undergo two procedures instead of one. And both tests require you to prepare by taking laxatives to clean out your colon 24 hours before the procedure. In the NNMC study, 54 percent of patients said that virtual colonoscopy was more uncomfortable than the conventional procedure, which the researchers attributed to lack of sedation for the virtual scan. I had a virtual colonoscopy last year and found it quite tolerable.

At the moment, virtual colonoscopy is not widely available and not all doctors who perform colonoscopies have been trained in the new method. Cost may limit its use, too, especially if insurance companies decline coverage.

Andrew Weil, M.D.

Creative Commons License Some Rights Reserved Creative Commons Copyright Notice
A portion of the original material created by Weil Lifestyle, LLC on DrWeil.com (specifically, all question and answer-type articles in the Dr. Weil Q&A Library) is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.

The Weil Vitamin Advisor
Get your FREE personalized vitamin recommendation & supplement plan today!

Dr. Weil on Healthy Aging
Your Online Guide to the Anti-Inflammatory Diet. Start eating for your health - begin your free trial now.

Dr. Weil's Spontaneous Happiness
Achieve emotional well-being
in just eight weeks!
Start your 10-day free trial now!

Vitamin Library
Supplement your knowledge with Dr. Weil's essential vitamin facts. Learn why they are necessary and more.

Dr. Weil's Optimum Health Plan
Your 8-week plan to wellness.
Begin your journey today!
 

Dr. Weil's Head-to-Toe
Wellness Guide

Your guide to natural health.
Use the Wellness Guide today!

Dr. Weil's Anti-Inflammatory Diet Food Pyramid
Our interactive tool can help improve overall health through diet.

Condition Care Guide
Learn about health conditions from acne to vertigo, and Dr. Weil's view of the best treatment options for each.

Healthy Recipes
Discover a treasure trove of healthy, healing foods and creative, delicious ways to prepare them.

Q&A Library
Over 2,000 questions from you
and their corresponding answers
from Dr. Weil.

 
Copyright © 2014 Weil Lifestyle, LLC
Information on this web site is provided for informational purposes only and is not intended as a substitute for the advice provided by your physician or other healthcare professional. You should not use the information on this web site for diagnosing or treating a health problem or disease, or prescribing any medication or other treatment.

Ad Choice
Advertising Notice

This Site and third parties who place advertisements on this Site may collect and use information about your visits to this Site and other websites in order to provide advertisements about goods and services of interest to you. If you would like to obtain more information about these advertising practices and to make choices about online behavioral advertising, please click here