Background: Irritable bowel syndrome(IBS) is a common GI complaint. Since there exist some controversies with reference books regarding the clinical and pathological findings, the present study was conducted to determine the clinical, paraclinical and pathologic findings of irritable bowel syndrome in a group of patients.

Materials and methods : For this descriptive study, 80 patients who had been diagnosed as IBS according to the ROME criteria were selected. Other diseases were excluded by complementary studies. Colonoscopy and barium enema was performed and multiple biopsies were obtained.

Results : The study population included 42 males and 38 females with the mean age of 26.5±7 years. The most common chief complaints were flatulence, abdominal pain, and diarrhea. Pathologic findings were revealed in 77 cases (96.3%).

Conclusion : High prevalence of pathologic changes is a unique finding in our patients. Further studies regarding the diagnostic modalities and proper treatment are suggested.