ENDOSCOPIC EVALUATION OF CHRONIC HUMAN IMMUNODEFICIENCY VIRUS-RELATEDDIARRHEA - IS COLONOSCOPY SUPERIOR TO FLEXIBLE SIGMOIDOSCOPY

Objectives: In patients with chronic human immunodeficiency virus (HIV )-related diarrhea undergoing lower endoscopy, the decision tea perfor m flexible sigmoidoscopy or colonoscopy is controversial. The purpose of this study is twofold: 1) to evaluate the diagnostic yield of colon oscopy in a large group of patients with chronic HIV-related diarrhea and negative stool studies, and 2) to determine whether colonoscopy is superior to flexible sigmoidoscopy in this setting. Methods: All HIV- infected patients with chronic diarrhea who were referred for diagnost ic colonoscopy at Bellevue Hospital Center between January 1992 and De cember 1996 were identified. Patient charts, pathology reports, and en doscopy records were reviewed. Results: During the 5-yr study period, 317 consecutive patients with chronic unexplained diarrhea undergoing colonoscopy were identified. A potential cause of diarrhea was found i n 116 patients (36.6%). Cytomegalovirus was the most common pathogen d etected (24%), The yield of colonoscopy was significantly higher in pa tients with a CD4 count of <100 cells/mm(3) than in those with higher CD4 counts (44.8% vs 6.4%, p < 0.0001). Thirty percent of pathogens an d 75% of lymphomas were identified only on biopsies taken from the pro ximal colon, well beyond the reach of the flexible sigmoidoscope. Impo rtantly, 94% of the pathogens that were found only in the proximal col on were organisms for which effective therapy is currently available. Conclusions: Colonoscopy is superior to flexible sigmoidoscopy in HIV- infected patients with chronic unexplained diarrhea. If flexible sigmo idoscopy had been performed instead of colonoscopy, 30% of pathogens w ould have been missed and 75% of lymphomas would have escaped detectio n. (C) 1998 by Am. Coll. of Gastroenterology.