ABSTRACT
Microscopic colitis has been generally recognized as lymphocytic colitis and collagenous colitis: two inflammatory diseases of large intestine without a definite origin. The colon appears normal by colonoscopy. So, biopsy of the colonic mucosa is mandatory for diagnosis. As a descriptive design we assessed epidemiological, clinical and laboratory findings of patients diagnosed as microscopic colitis from 2001 to 2003, retrospectively. This study had been conducted in one of the University related clinics in Tehran. Results: In this setting, 12 patients were diagnosed as microscopic colitis [3 collagenous colitis, and 9 lymphocytic colitis]. Most of these patients were female [11 patients]. The average of the patients' age at the time of the diagnosis was: 47.6 +/- 18.1 years. The delay of diagnosis was distributed from 2 months to 27 years [average: 8 years]. The most prominent complaint was diarrhea [100%]. Most of the cases were presented as a chronic intermittent manner [6 patients- 50%]. Hyperthyroidism, atrophic gastritis, and type 1 diabetes mellitus, each of them were detected in 3 separate patients. After treatment initiation, recurrence of the disease was not seen during 2 years of follow-up. Most of the time, microscopic colitis is mis-diagnosed as irritable bowel syndrome. Clinical suspicion plays the main role in diagnosis of microscopic colitis cases among patients with watery diarrhea and normal colonoscopy