Everyone knows toxins are bad. Many people, especially those interested in or practicing nontraditional medicine, believe that certain toxins accumulate in our bodies, causing disease and essentially poisoning us. This concept is known as autointoxication. By detoxifying the body, the reasoning goes, we can purify ourselves and restore our health.

The idea isn't new. Greeks and Egyptians believed in autointoxication, and the concept was popular in the United States in the early 20th century, too. Colon cleansing -- the controlled irrigation of the bowel using a specially designed apparatus operated by a trained practitioner -- was also popular, and the first device for the procedure appeared about a hundred years ago. At least part of its popularity was due to grander and grander claims about the benefits of colon cleansing. (The early 20th century was a good time to be an unscrupulous huckster, especially of tonics or medical devices.)

Colonic irrigation as a treatment for autointoxication fell out of favor after excessive advertising claims led many people to write off the treatment as quackery. Around the same time, doctors and patients began placing their faith in drugs to treat illnesses, instead of physical therapies. The American Medical Association largely ridiculed colon cleansing and the idea that toxins are responsible for illness, and the theory of autointoxication plummeted in popularity.

In recent years, colon cleansing has come back into vogue. Some of those unproven claims are being made once again, and the medical community largely greets the practice with skepticism (if not outright derision), just as it did in the past.

Colon cleansing has been hailed in modern times as a treatment or cure for everything from fatigue to cancer. It has even been proposed that colon cleansing can protect you from 2009's H1N1 virus [source: Evans]. Online marketers of colon treatments aren't afraid to share images showing what they claim are disgusting blockages that have been retrieved from clients' colons. It's not a bad pitch -- if that rubbery goo was lodged in your body as claimed, it wouldn't be unreasonable to want to remove it.

Detractors, on the other hand, claim we don't carry around stored-up waste over long periods of time, and that colon cleansing is an unproven remedy. Even worse, critics point out, it can be dangerous and even deadly.

So, is colon cleansing a good idea? Click to the next page to find out.