Frequency of microscopic colitis in patients presenting with chronic diarrhea.

Objective: To evaluate frequency of microscopic colitis in patients presenting with chronic diarrhea at a tertiary care hospital in Karachi, Pakistan. Study Design: Descriptive Cross-sectional study. Setting: Department of Gastroenterology, Liaquat National Hospital, Karachi, Pakistan. Period: January, 2022 to June, 2022. Material & Methods: Patients presenting in out-patient department of age >18 years of any gender with history of diarrhea >1 month, normal thyroid tests, negative serology for Celiac disease (Anti TTG IgA and IgG), and normal colonoscopy findings including terminal ileum were enrolled in the study after written informed consent. MC diagnosis was established using clinical diarrhea history and colonic biopsy findings. Results: Total 130 patients were analyzed with median age of 38 (IQR= 28-55) years. Nearly half were females (n=67, 51.5%). All patients had normal colonoscopy findings. Out of 130 patients, microscopic colitis was seen among 7(5.4%) cases out of which 5(3.8%) had lymphocytic colitis and 2(1.5%) had collagenous colitis. Patients with and without MC shared the same characteristics. Conclusion: A lower microscopic colitis frequency was found in the studied sample. Lymphocytic microscopic colitis is predominant than collagenous microscopic colitis.