Constipation (search) has been misunderstood for far too long, and it’s high time that changed. So say four doctors who want to set the record straight on constipation.

The doctors come from Germany, England, Italy, and the U.S. They pooled their knowledge to see what does — and doesn’t — make a difference in constipation.

Constipation is one of the most common health problems in the Western world.

But familiarity hasn’t brought scientific insight. Many strong beliefs about constipation haven’t been confirmed through studies.

“Certitude is not the same as correctness,” say the doctors, who included Stefan Müller-Lissner, MD, of Germany’s Park-Klinik Weissensee.

To separate science from folklore, the doctors reviewed studies on constipation. They covered everything from fiber to laxatives (search) to hormones. Here’s a quick look at their findings:

—Laxatives aren’t likely to be addictive.

—Except for the most severe cases, most laxative users don’t develop a tolerance for laxatives that requires them to keep increasing their dose.

—Stimulant laxatives probably don’t harm the colon and haven’t been shown to increase colorectal cancer (search) risk. However, chronic constipation appears to be linked to a higher risk of colorectal cancer.

—Unless someone is dehydrated, drinking more fluids hasn’t been shown to help.

—Increasing dietary fiber helps some patients, but makes other cases worse. For elderly patients, becoming more active can help. But younger people with severe, chronic constipation may not reap the same benefit.

—There is no evidence that diseases are caused by absorbing toxins from stools.

—Women’s sex hormones have little impact on constipation during the menstrual cycle. However, hormones during pregnancy may increase constipation.

—Underactive thyroids can cause constipation, but it’s rarely seen in constipation patients.

The study appears in the American Journal of Gastroenterology’s January edition.

By Miranda Hitti, reviewed by Michael W. Smith, MD

SOURCES: Müller-Lissner, S., American Journal of Gastroenterology, January 2005; vol 100: pp 232-242. WebMD Medical Reference from Healthwise: “Constipation, Age 12 and Older —Topic Overview.”