Beyonce reportedly does it. So do Kim and Khloe Kardashian. What's the fad these and other celebrities have embraced? Colon cleansing.
There has been a lot of debate over the usefulness of colon cleansing. Proponents believe it helps purify the body and treat certain diseases. But a new report published today says colon cleansing offers no benefits and can actually be quite dangerous.
Colon cleansing has been around for centuries, and it's based on the theory that waste products build up in the colon that can enter the bloodstream and poison the body. Colon cleansing can be accomplished in a variety of ways, including supplements and the enema-like practice of flushing out the colon with water and other substances such as coffee.
"Despite colon cleansing's long history and current popularity, the literature does not support its purported benefits," wrote the report's authors, led by Dr. Ranit Mishori, clinical faculty at Georgetown University School of Medicine in Washington, D.C.
Mishori and her colleagues reviewed published case studies and found that most of them noted numerous adverse effects from colon cleansing. They ranged from mild cramping and nausea to serious effects such as kidney failure.
Mishori said that she and other doctors at Georgetown University Hospital have seen an increasing number of patients who have suffered the ill effects of colon cleansing as well as patients who have asked about it, which is why she decided to undertake this research.
In addition to the side effects of colon cleansing, the authors warned that the Food and Drug Administration has not approved the devices used for colon hydrotherapy, the procedure that uses water to flush out the large intestine.
Some of the equipment is FDA-approved for use only for cleaning out the colon before a medical procedure, such as surgery. It is not approved, however, to clean out the colon for non-medical reasons. Dietary supplements used for colon cleansing are not subject to pre-approval by the FDA before they are marketed, but they must not make false or misleading claims.
The equipment may not be sterilized properly, and the authors noted is that practitioners known as hydrotherapists are not licensed by scientifically-based organizations.
While it may seem as if it's only an enema, colon hydrotherapy uses much more water than a standard enema.
"Hydrotherapy is extreme enema, and it can be harmful," Mishori said.
"You can get into quite a lot of trouble doing repeated enemata, including serum electrolyte imbalance from absorption of the fluids used," said Wendie Howland, a nurse and health care consultant.
Physicians told ABC News they are often asked about the benefits of colon cleansing.
"I keep it simple - I say, it can't help you, but it could hurt you, so don't do it," said Dr. Roshini Rajapaksa, assistant professor of medicine at NYU Langone Medical Center.
"I do my best to convince patients against undergoing this potentially dangerous intervention," said Dr. Gerard Mullin, associate professor of medicine at Johns Hopkins Hospital in Baltimore.
Those opposed to the practice debunk the idea that detoxification is necessary.
"Statements about stool residing in the colon for years or many pounds of waste being in the colon are simply not true, but widely believed by the public," said Dr. John Allen, a spokesperson for the American Gastroenterological Association.
Colon cleansing is especially dangerous for people with certain medical conditions, such as Crohn's disease and other gastrointestinal problems, diabetes and conditions requiring specific medications.
But other health care providers stand by the benefits of colon cleansing. Those who spoke out in favor of the practice referred mostly to colon hydrotherapy, not over-the-counter oral supplements.
"I can find no cons in doing colon hydrotherapy. It's very beneficial to health," said Dr. Edgar Guess, medical director of the Beverly Hills Wellness Center. "Cleansing the colon is healthy."
"It is absolutely wrong that it's OK to have just two or three bowel movements a week," he added.
Those who practice colonic irrigation say benefits include healthier skin, more energy, a stronger immune system and fewer problems with constipation.
"In people who are constipated, greater than 90 percent of toxins -- cholesterol, bile, etc. -- can be reabsorbed. Colonics ensure that during the detox process, little will be reabsorbed into the system, thereby increasing the effectiveness of removing toxins from the body," said Dr. Korey DiRoma, a naturopathic physician at the Center for Integrative Health and Healing in Bennington, Vt.
Advocates of colon hydrotherapy say it's safe if it's done by licensed practitioners. The International Association for Colon Hydrotherapy says only the state of Florida licenses hydrotherapists. The association is pushing for more states to provide licensing.
Mishori said she can understand people's desire to rid their bodies of "gunk," but said there are safer and more effective ways to do it.
"The problem is the body already does it on its own," she said. "The body is designed to detoxify itself."
"There are also other ways to do it, including diet and exercise," she added.