A hydro-therapist starts an intestine cleaning spa with a stomach massage and then putting a tube inside the client. Photo: Courtesy of Wang Li

Under what circumstance are you willing to tolerate inserting a tube into your anus? Some people would actively avoid this.

However, other Beijingers cheerfully pay to flood their colons with an intestine cleaning spa treatment, which is especially popular amongst people who want to lose a few pounds instantaneously.

Maggie Liu, 26, goes for colon cleanses almost every two weeks, at about 100 yuan a plop, to cure her constipation.

"I was nervous when I took the treatment for the first time. But you should remember to relax so that it won't hurt too much," said Liu.

"You might have a flabby stomach, but it will sink down immediately after the therapy," added Liu, noting that with the help of some medicines, her symptoms of constipation and menstrual pain both declined.

"It hurts a little, and you feel as if you were having diarrhea during the treatment," she said.

"One of the reasons I do this is that I heard Soong May-ling (wife of Chiang Kai-shek) did intestine treatments regularly, and lived until 106 years old," said Liu.

Wang Li, manager and hydro-therapist from the Lüsexianying Women's Spa in Xicheng district, explained, "The intestines are in charge of expelling about 85 percent of the toxins inside one's body, and colon cleaning spas can help to speed it up."

Before she opened the spa in 2007, Wang says she was trained as doctor of traditional Chinese medicine. The therapists at Wang's spa are asked to train and practice for about three years.

Wang said the colon treatment is especially popular among female clients over 20.

She said her customers may be a little bit afraid when they do it for the first time, but most of them feel very comfortable after the treatment, and their sleep qualities and moods are improved too.

During the treatment, which usually lasts 30 minutes to an hour, people get a massage on the stomach first to loosen up the bowels, said Wang.

Then a bag of distilled water, combined with a small quantity of natural ingredients such as green tea powder, beer yeast, and aloe powder, will go through a tube inside one's intestines, "kind of like an intravenous infusion," said Wang.

Then about 5 to 10 minutes later, people can just go to the toilet to eliminate the stools, water, as well as the toxins. "Some clients may lose more than 2 kilograms of weight the first time, and even more the next time," said Wang, noting there usually are immediate results.

There are also household machines and tools available on the market for people to do a colon cleaning at home. 

So does it work?

"Many beauty salons are boasting about this method, saying it can improve one's looks and help to lose weight, but I think it's neither scientific nor effective at all," said Li Chunyu, a doctor and the director of the anorectal department of The Fourth Affiliated Hospital of China Medical University.

Colon cleaning is a therapeutic method in western medicine, usually used before a surgery or a colonoscopy, said Li.

"Regular cleaning does no good to one's body. Instead it does damage to the environment for intestinal flora, and it also upsets the fluid, electrolyte and acid-base balance inside one's body," Li explained.

Li suggests people who are troubled with constipation or obesity should drink plenty of water, exercise more and adopt a healthier diet with food of high crude fiber. They should occasionally take medicine that can improve bowel movements. "If you don't need the cleaning for medical reasons, don't do it," said Li.

"It's very normal if a client feels swelled up and it hurts a little," said Wang, noting that they are trained to put only about 5 millimeters of the tube inside the client's body, but the tube is longer in a hospital. "The cleaning services in hospitals are for medical purposes, and we do this to preserve health," said Wang.