Proponents of colon cleansing believe that toxins from your gastrointestinal tract can cause a variety of health problems, such as arthritis, allergies and asthma. They say that colon cleansing — also called colonic irrigation — removes these toxins, thus promoting healthy intestinal bacteria, boosting your energy and enhancing your immune system.

While there is little scientific evidence to support or refute the benefits of colon cleansing, critics say it's generally unnecessary and at times may even be harmful. Although doctors prescribe colon cleansing as preparation for medical procedures such as colonoscopy, most don't recommend it for detoxification. Their reasoning is simple: The digestive system and bowel naturally eliminate waste material and bacteria — your body doesn't need enemas or special diets or pills to do this.

One concern with colon cleansing is that it can increase your risk of dehydration. A potentially more serious concern is that certain laxatives used in colon cleansing, such as those with sodium phosphate, can cause a rise in your electrolytes, which can be dangerous if you have kidney disease or heart disease.

The FDA classifies colonic irrigation systems as Class III devices that cannot be legally marketed except for medically indicated colon cleansing (such as before a radiologic endoscopic examination). No system has been approved for "routine" colon cleansing to promote the general well being of a patient. Since 1997, the agency has issued at least seven warning letters related to colon therapy:

* In 1997, Colon Therapeutics, of Groves, Texas, and its owner Jimmy John Girouard were warned about safety and quality control violations of the Jimmy John colon hydrotherapy unit and related devices [13].

* In 1997, Tiller Mind & Body, of San Antonio, Texas and its owner Jeri C. Tiller, were ordered to stop claiming that their Libbe colonic irrigation device was effective against acne, allergies, asthma and low-grade chronic infections and improved liver function and capillary and lymphatic circulation [14].

* In 1997, Colon Hygiene Services, of Austin, Texas and its owner Rocky Bruno was notified that their colonic irrigation system could not be legally marketed without FDA approval [15].

* In 1999, Dotolo Research Corporation, of Pinellas Park, Florida, and its chief executive officer Raymond Dotolo were warned about quality control violations and lack of FDA approval for marketing its Toxygen BSC-UV colonic irrigation system [16].

* In 2001, Clearwater Colon Hydrotherapy, of Ocala, Florida, and its vice president Stuart K. Baker were warned about quality control violations and lack of FDA approval for marketing their colonic irrigators [17].

* In 2003. the International Colon Hydrotherapy Association, of San Antonio, Texas and its executive director Augustine R. Hoenninger, III, PhD, ND, were notified that it lacked FDA approval to sponsor "research" that had been proposed or actually begun on the devices of five companies [18].

* In 2003, Girourd and Colon Therapeutics were notified that his devices require professional supervision and cannot be legally marketed directly to consumers. The letter noted that he had obtained marketing clearance only for use in medically indicated colon cleansing, such as before radiologic or sigmoidoscopic examinations [19].

* In 2003, the Wood Hygienic Institute of Kissimmee, Florida, and its owner Helen Wood were warned about quality control violations and the use of unapproved therapeutic claims in marketing their devices [20].