Health-related quality of life and the utilization of health resources are important components of the evaluation of patient outcome in HIV infection because medical problems are often progressive and debilitating, and treatment is palliative. We evaluated quality-of-life measures and resource utilization of patients with AIDS and/or CD4 lymphocytes < 200 who had symptoms of chronic diarrhea and compared them with similar patients with AIDS and/or CD4 lymphocytes < 200 without diarrheal symptoms. Annual charges were 50% higher for patients with chronic diarrhea ($24,567 versus $14,471 for the comparison group, p < 0.01). Higher charges for the patients with diarrhea were a result of more physician visits and diagnostic testing. Quality-of-life scores were poor for all patients, but deterioration over the year in role functioning (social activity, daily living, energy, cognition) and general health was clearly evident (p < 0.01) for the patients with chronic diarrhea. These patients also suffered significant work loss and reported greater need for assistance in the home. These data suggest that HIV-infected patients with diarrhea experience marked decreases in quality of life and that care for patients with chronic diarrhea is costly. Relatively little attention has been paid to this debilitating syndrome, and current treatment options rarely provide permanent relief. Research and innovation in this area are needed; an estimated 25-50% of HIV-positive individuals suffer from this symptom complex.