Colon ischemia, the term applied broadly to all forms of ischemic injury to the colon, has gained prominence as a complication of alosetron treatment for irritable bowel syndrome with diarrhea (IBS-D). A barrier to the interpretation of this finding, however, is the paucity of quantitative information on the incidence or determinants of colon ischemia.

As reported in the July 2004 issue of The American Journal of Gastroenterology, Alexander Walker, MD, DrPH, and colleagues examined demographic and clinical characteristics of, and previous health care use by, patients with presumed colon ischemia to identify predictors of this condition. Insurance data between 1995 and 1999 were used to identify 700 individuals with presumed colon ischemia and 6440 controls.

Analysis showed that patients with colon ischemia were nearly 3 times as likely as controls to have IBS. In addition, a history of nonspecific colitis, lower gastrointestinal tract hemorrhage, systemic rheumatic disorders, ischemic heart disease during the preceding 6 months, or abdominal surgery during the past month was much more common among patients with colon ischemia than among controls. The most prevalent risk factor for colon ischemia was use of drugs associated with constipation as an adverse effect.

The authors concluded that clinically evident colon ischemia occurs preferentially in individuals with previous abdominal complaints, IBS, or both. In addition, drugs that reduce bowel motility may constitute a widespread and potentially avoidable risk factor.