Importance of Biopsies and Histological Evaluation in Patients with Chronic Diarrhea and Normal Colonoscopies

BACKGROUND In patients with chronic diarrhea, colonoscopy may identify inflammatory causes or some occult disease, and also can show a normal mucosa. Serial biopsies of intestinal mucosa can be useful for a differential diagnosis, and to modify the treatment. AIM To evaluate whether the biopsies performed in patients with chronic diarrhea and a normal colonoscopy contribute to the differential diagnosis and alter the therapeutic approach. METHODS A descriptive, retrospective and cross-sectional study using a computerized database was done. Patients with chronic diarrhea and a normal colonoscopy underwent serial biopsies of the terminal ileum, ascending colon and rectum. RESULTS From 398 records, 214 were excluded. Of the 184 patients enrolled, 91 showed histological changes: 40% nonspecific inflammation; 5.18% lymphocytic inflammation, 10.37% eosinophilic inflammation; 39.26% lymphoid hyperplasia; 2.22% collagenous colitis; 2.22% melanosis; and 0.74% pseudomelanose. The sites with the largest number of changes were the terminal ileum and right colon. CONCLUSIONS Serial biopsies in patients with chronic diarrhea and normal colonoscopy identified changes in almost 50% of cases and 22% of these cases may had modified the treatment after identification of collagenous, lymphocytic and eosinophilic colitis.