How clean is your colon? If you’re tempted to find out by getting a colon cleanse, don’t bother. You’re quite likely to develop complications from the procedure and there’s no evidence that flushing out your colon has any health benefits.
That’s the conclusion researchers reached after reviewing 20 studies on colonic cleansing. Dr. Ranit Mishori and her team at Georgetown University School of Medicine and Providence Hospital report in the Journal of Family Practice that colonic cleanses — whether with water or via supplements or herbal remedies, don’t actually do much — other than potentially cause some uncomfortable, and in some cases dangerous side effects.
Spas and wellness facilities like to tout the “detoxifying” benefits of colonic cleanses, and these claims include improvements in well-being and energy and even weight loss. Some remedies go so far as to list boosts in immune function.
The concept is certainly alluring — stress, not to mention our unhealthy diets and the various chemicals and pollutants we’re exposed to everyday — can build up in our gut, slowly poisoning us from the inside out. Why not periodically clean out the system and start anew?
The problem with that argument, says Mishori, is that there is no medical evidence to support it. Colonic cleanses were popular more than a century ago, until the American Medical Association quashed any notion that the practice was worthwhile by condemning cleanses as not medically necessary in 1919. But in recent years, celebrities, with the help of heavy marketing by spa facilities, have brought the cleanses back. Nothing, however, has changed on the medical front.
“I totally understand where people are coming from in wanting to detoxify,” says Mishori, “You want to get all the gunk out. But there is no evidence that [the cleanses] are doing anything, and physiologically it doesn’t make sense. The body has a system for detoxifying itself — it’s called pee and poop. And for healthy people, that’s all it takes.”
And while the idea of cleaning out the intestines sounds like a good idea, you actually need a good growth of bacteria in your gut to ease digestion and voiding of waste.
But what concerned Mishori and her team wasn’t simply the fact that patients didn’t appear to be getting any benefit from the cleanses, but that the procedures were causing harm. “Every time you put something where it’s not supposed to be in the body, you can poke tissue, make holes and disrupt architecture,” she says. And that’s exactly what the studies found. Those who underwent colon hydrotherapy, in which technicians insert a tube in the rectum and flood the colon with liters of fluid, often water, experienced infections and complications from bacteria that were introduced into the colon or from accidental punctures made by the hose.
People who opted for less invasive methods, including supplements, teas, laxatives, or herbal remedies to empty the colon didn’t necessarily fare any better — they experienced cramping, abdominal pain, nausea, vomiting, and, in severe cases, imbalances in their electrolytes and kidney failure.
Dick Hoenninger, executive director of the International Association for Colon Hydrotherapy, a professional organization that certifies technicians in the procedure, says the group is aware of well-being claims made for colon cleansing, but notes that there isn’t much science behind them. “We suggest to our therapists and anybody doing colon hydrotherapy that it should be done for medically indicated purposes and at the indication of a physician,” he says.
Indeed, the only reasons for which the FDA approves colon hydrotherapy devices that use fluids to cleanse the colon, are medical needs such as to clean out the colon before a radiological exam, or colonoscopy, or for constipation. But ironically, while people are willing to undergo cleansing for unproven purposes of well-being, under the premise that they are detoxifying themselves, they’re a little less willing to get the procedure done when it might actually lead to medical benefits. Cleansing with laxatives or other remedies, for example, is similar to the preparation required before a colonoscopy to check for cancerous lesions, but many people would rather risk missing the tumor than subject themselves to the discomfort of emptying out their colon.
That may speak to the fact that spas and wellness facilities might be better at marketing their services than doctors. But given the lack of evidence supporting the practice, the benefits of colon cleansing, it seems, remain more psychological than physiological.
Alice Park is a writer at TIME. Find her on Twitter @aliceparkny. You can also continue the discussion on TIME’s Facebook page and on Twitter @TIME.