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The Shambulance: 5 Reasons Not to "Cleanse" Your Colon

By Elizabeth Preston
Jul 4, 2014 2:22 PMMay 21, 2019 7:33 PM


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Happy Independence Day! Here’s hoping all your fireworks are experienced externally. This post first appeared in October 2012.


The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. Physiologist Steven Swoap is with me at the helm.


If you’ve been tempted by promotions for “colon hydrotherapy”—that is, sessions in which you would pay someone to put a tube up your rectum and wash out your large intestine with water, like a dirty garage being hosed down in summer—then you’ve already overcome some impressive mental hurdles. Maybe you’re almost ready to enjoy the relaxation, renewed energy, and improved health that the procedure promises. Before you take the plunge, as it were, here are a few points to consider.

It’s not the 19th century. People who offer colon hydrotherapy (also called a colonic) tell you the large intestine is full of “toxic waste and toxins.” It does, of course, carry waste out of your body. But is it a two-way street?

“Intestinal autointoxication,” the idea that poisons from your feces can move backward from your colon into the rest of your body, is an old one. Old as in ancient Egyptian. The Greeks were into it too, including Hippocrates and Galen.

In the 19th century, doctors prescribed laxative pills and enemas to cure all manner of illnesses. One man created and promoted a popular device called the Cascade. As alternative medicine researcher Edzard Ernst describes it, this was a rubber bottle with a nozzle for a person to insert into his or her rectum. When the person then sat on the bottle, it squirted 5 liters of fluid into up into the colon.

By the 1920s, though, some actual scientific study had been done on the subject. Unlike the Cascade, the theory of intestinal autointoxication did not hold water.

A toilet is not a gym. “Having colonics is like taking your colon to the gym,” declares the website for one colon hydrotherapy center. Filling the colon up with water and emptying it again, the theory goes, “exercises” the intestinal muscle so it can do its job better in the future.

“Injecting water into the colon will cause the colon to swell, and cause so-called ‘stretch-activated’ contractions of the smooth muscle surrounding the intestine,” says Williams College physiologist Steven Swoap. These contractions are called peristalsis. “But the colon does this naturally as food stuffs pass through,” he adds. “There is definitely no need to help this along for peristalsis to occur.”

Colorectal surgeon Francis Seow-Choen points out in a review paper that since the colon is lined with smooth muscle (a type we can’t voluntarily control), it cannot be toned like the muscles you work at the gym. Toned muscles are ones that we’ve consciously flexed so often, our brains learn to flex them automatically. Sit-ups work; water up the rectum doesn’t.

It’s rude to firehose your friends. In addition to waste, your colon houses a large portion of your body’s friendly bacteria. These gut microbes manufacture several vitamins we need, and seem to be involved in defending us from dangerous microorganisms and generally keeping us healthy.

One study found that cleaning the colon to prepare patients for a colonoscopy—in this case with a straightforward laxative, not with large volumes of pumped-in fluid as in a colonic—immediately altered the types of bacteria in patients’ intestines. Another study found that cleaning out the colon both knocked down the bacterial population there and seemed to make it easier for new, potentially unfriendly bacterial strains to move in.

It might kill you. “My biggest worry would be perforations caused by the water,” Swoap says. “If abrasions or tears in the colon occur, you have the possibility of a dangerous bacterial infection.” Ironically, one way to make the material in your colon as dangerous as colonic practitioners claim is to blast it with water. Breaking up the feces and creating tiny tears in the colon can turn a one-way street into a two-way hazard.

According to a paper in the Journal of Family Practicereported complications from colon cleansing include cramping, abdominal pain, vomiting, rectal perforation, blood poisoning, kidney failure, fatal amoebic infection, and fatal accumulation of gas in the veins. Even if such a consequence is rare, Swoap points out, “it is sure not to happen if I don’t let some technician put a hose in my rear.”

Everybody poops. Colons have been doing their job without outside intervention for hundreds of millions of years. “Your colon does not need help in a non-disease state,” Swoap says. “Your colon is a pro!” If you want to thank it, step away from the hose and have some broccoli.

Image: Mykl Roventine

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