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.
--Patricia Raymond, MD
Gastroenterologist
Assistant Professor of Clinical Internal Medicine
Eastern Virginia Medical School
Norfolk, VA
Founder of YourHealthChoice.net

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.