Background: Claims of marked health benefits from “detoxification” have stimulated public interest in colonic cleansing and generated a multimillion-dollar industry promoting oral agents, colonic hydrotherapy, or enema therapies designed to empty the bowel. Questions about colonic cleansing are among the most common inquiries to the American College of Gastroenterology and are often posed to family physicians. Acosta and Cash reviewed the evidence of benefit and risk of harm from colonic cleansing to better inform physicians and the public.

The Study: The authors searched Medline, EMBASE, and the Cochrane Collaboration Database to identify relevant articles published between 1966 and 2008. They also reviewed abstracts from gastroenterology subspecialty conferences and the alternative medicine subset of PubMed. The bibliographies of all identified articles were reviewed for additional articles of interest.

Potentially relevant articles were independently assessed by each of the two authors for relevance and methodologic quality. The eligible articles were then reviewed in a blinded manner; investigators abstracted data concerning the population studied, condition of interest, intervention, measured outcomes, and adverse events. A formal meta-analysis was not possible because of the heterogeneous methodologies of the reported studies.

Results: From 297 potential citations, 16 articles and one letter met criteria for inclusion in the study. Only two clinical trials were identified. Case reports, case series, and reviews accounted for the other material. None of the articles were of good methodologic quality. Eleven articles had quality scores in the middle tertile and six had scores in the lowest tertile.

No eligible articles were identified concerning the effect of colon cleansing on general health or on specific conditions such as hypertension, asthma, irritable bowel syndrome, ulcerative colitis, arthritis, sinus congestion, or alcoholism. One study reported that heroin withdrawal symptoms resolved more quickly and abstinence rates were higher in addicts who received colonic hydrotherapy and Chinese herbal medicine in addition to medical treatment, but the methodology and end points of this study were obscure and questionable.

Adverse events such as electrolyte imbalances, septicemia, colitis, rectal perforation, and death were reported. In an outbreak of amebiasis attributed to colonic irrigation therapy at a single clinic, at least 36 patients were infected, 10 required colectomy, and six died.

Conclusion: The authors report the notable lack of good-quality published evidence of any health benefit from colonic cleansing and the many publications concerning adverse events, including death. They draw attention to the long history of the practice, and to the wide range of herbs and other substances, especially coffee, that are commonly administered in the hydrotherapy or enema fluid. Although the medical literature may have a publication bias towards adverse events, the authors conclude that colonic cleansing cannot be recommended because of the overwhelming lack of evidence of health benefit and significant evidence of harm.