Gastrointestinal symptoms are commonly seen in patients with established AIDS. We examined the charts of 258 HIV-infected patients attending our HIV outpatient clinic to determine: (1) the frequency of gastrointestinal symptoms in unselected HIV-infected patients and (2) if there are any predictors of the development of symptoms in initially asymptomatic patients. We found the overall frequency of gastrointestinal symptoms at initial presentation in our ambulatory, predominantly homosexual population of HIV-infected patients was 35% (95% CI 30-40%) with 19% having anorexia, 15% weight loss, 14% diarrhea, and 5% dysphagia. There was no association between the presence of symptoms and stool parasites, which were found in 51% of patients. In 165 patients who were initially asymptomatic, 72% subsequently developed symptoms over 36 months of actuarial follow-up. Patients with initial T4 counts < 500 were more likely to develop symptoms. Patients with a greater degree of immunosuppression as indicated by a lower T4 count, are more likely to develop gastrointestinal symptoms.