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.”