The prevalence of chronic diarrhea among diabetic patients

OBJECTIVE: The prevalence of chronic diarrhea in patients with type I and t ype II diabetes is uncertain, most data being available from tertiary refer ral centers. We report the prevalence and etiology of chronic diarrhea in 8 61 heterogeneous diabetic patients attending a primary care diabetic outpat ient clinic. METHODS: All patients attending the clinic were asked to fill in a question naire relating to their bowel habits. Patients who fulfilled the criteria f or chronic diarrhea underwent a comprehensive workup to define the cause of the diarrhea. Additional parameters were the mean duration of diabetes, he moglobin-A1c levels, and the presence of autonomic neuropathy. RESULTS: Chronic diarrhea was diagnosed in 32 patients (overall prevalence of 3.7%). The prevalence of nondiabetic diarrhea was higher among type I di abetic patients than among type II patients (3.29% vs 2.3%), although it di d not reach statistical significance. Diabetic diarrhea was more common amo ng type I than type Il diabetic patients (5.2% vs 0.4%, respectively, p < 0 .01). The most common cause of nondiabetic diarrhea was medication induced (metformin). CONCLUSIONS: Chronic diarrhea is more frequent in type I diabetic patients. The higher prevalence of diarrhea in this population can be attributed to diabetic diarrhea (which is quite rare in type II patients). The most commo n cause of nondiabetic diarrhea is drug therapy with metformin. (Am J Gastr oenterol 1999;94:2165-2170. (C) 1999 by Am. Coll. of Gastroenterology).