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.