Commonly asked questions & answers about gastrointestinal conditions.

Q I've heard about something called a "virtual colonoscopy." I'm interested in this because I don't want to have a regular colonoscopy. Where can I get one?

A It is actually called a virtual colonography, and it is an exciting new technology. Unfortunately, it is not quite ready for prime time. A virtual colonography uses x-rays and computers to produce two- and three-dimensional images of the colon. It can be performed with a CT scan or an MRI. However, studies find that the accuracy is best when viewed in three dimensions, and few medical centers have the necessary technology. You still need to undergo the night-before prep to clean out your colon, including using a suppository to remove all fecal matter from your anus, so, in terms of preparation, it's no easier than a traditional colonoscopy. Plus, if the screening identifies a polyp, you still need a colonoscopy to remove it. In addition, it is not often covered by insurance companies. Bottom line: I think it's just a matter of time before virtual colonographies become the gold standard for colon cancer screening, but we're just not there yet.

Q I've been hearing a lot about probiotics. I have irritable bowel syndrome. Could they help?

A I am so excited about probiotics--"good" bacteria or yeast that can rebalance the microbes in your gut, reduce inflammation and even protect against harmful bacteria or viruses. Probiotics have just entered the scientific era as we finally figured out that the gut is not supposed to be sterile, and that bacteria in the bowel are very important in terms of how well it functions. (12)

Eating live-cultured yogurt may give you all the probiotics you need. But if you have a specific problem, or if you're taking antibiotics (which kills all bacteria in your gut, not just the bad stuff), then you need to take specific organisms for your particular condition. For instance, if you've had the bacterial diarrheal infection C. difficile, which is treated with antibiotics, the yeast Saccharomyces boulardii can help recolonize the gut and prevent reinfection with this bacteria.

For IBS, studies find different benefits with different probiotics. For instance, Lactobacillus plantarum improved flatulence and pain, while Bifidobacterium infantis improved all symptoms. There are many types of probiotics, and more high-quality studies are needed to evaluate the efficacy in IBS.

Don't take probiotics on your own, however. Even though they are sold as natural supplements, they can have harmful side effects, just like any medicine. Probiotics are not regulated by the FDA. Therefore, most of the products you will find in the health food stores have not been tested in research studies to prove they work. Talk with your health care professional to come up with the best approach for your symptoms. Today, most gastroenterologists are supportive of probiotics and knowledgeable about their uses.

--Patricia Raymond, MD

Gastroenterologist

Assistant Professor of Clinical Internal Medicine

Eastern Virginia Medical School 

Norfolk, VA

Founder of YourHealthChoice.net

References

12 Quigley EM, Flourie B. Probiotics and irritable bowel syndrome: a rationale for their use and an assessment of the evidence to date. Neurogastroenteral Motil. 2007 Mar; 19(3):166.