---

Background and Objective: Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders characterized by abdominal pain or discomfort and altered bowel habits. Although IBS etiology is poorly understood, some psychological disturbances and food allergies have been proposed. This study was done to determine the effect of food allergen exculsion on symptoms and quality of life in IBS. Materials and Methods: In this descriptive and anolytical study was done on 100 IBS patients in Tabriz, Iran during 2011. Food allergies of specific origin and effects of non allergic regimens on quality of life, pain severity and disease symptoms were evaluted during one month period. Data were analyzed using SPSS-16, student’s t-test, Chi-Square and Fisher’s exact tests. Results: Patients age were 31.5±7.2 between 15-43 years. Specific antibodies against allergic foods were detectable in 31 (31%) cases. Penaut showed to induce the highest food allergy in 5 (16.1%) patients. The median disease duration was 4.5±2.6 years in allergic patients while 3.5±2.9 in non allergic group with no significant difference. The changes is quality of life was significant in non allergic regimens after one month in allergic group (P<0.05) while disease symptoms such as mucus defecation and flatulence had no significant changes. Conclusion: This study showed that one month non allergic regimens reduce abdominal pain and improve quality of life in IBS patients.