OBJECTIVE: Opportunistic disorders (OD) are the most frequent GI manifestations of the acquired immunodeficiency syndrome (AIDS). Since the introduction of highly active antiretroviral therapy (HAART), there appears to be have been a reduction in the incidence of many of these OD; however, the effect of HAART on the prevalence of GI OD has not been well studied. METHODS: From 4/95 through 3/98, all HIV (HIV)-infected patients undergoing GI endoscopy were prospectively identified; mucosal biopsies were obtained in a standardized fashion and histological specimens were examined by a single GI pathologist. Patients were divided into three groups based on the time of evaluation: group I: 4/95 to 3/96; group II: 4/96 to 3/97; and group III: 4/97 to 3/98. RESULTS: A total of 166 patients (90% men; mean age 36 ± 10 yr; median CD4 lymphocyte count 62 cells/μl, range 2-884, median viral RNA level 1,357 copies/ml, range undetectable to 7,721,715) underwent 279 upper and/or lower endoscopies during the study period. There were no statistical differences in patients' demographics and indications for endoscopy although the CD4 lymphocyte count was higher in group III. The percentage of patients receiving HAART at the time of endoscopy increased from 0% to 57% over the three periods (p < 0.01), and the percentage of patient receiving combination antiretroviral therapy increased from 37% to 82% over the study period (p < 0.01). In contrast, the prevalence of OD decreased from 69% (group I) to 13% (group III) (p < 0.01), whereas the prevalence of non-OD, including a normal endoscopy increased from 31% to 87% (p < 0.01). CONCLUSIONS: GI OD now seem to be an uncommon problem in HIV-infected patients undergoing endoscopy despite a low CD4 lymphocyte count, and this reduction of OD was associated with the use of HAART. (C) 2000 by Am. Coll. of Gastroenterology.