Effects of Mesalamine and Amitriptyline on Irritable Bowel Syndrome

Inclusion Criteria: 1. Establishment of diagnosis of IBS by ROME-III criteria 2. Age \> 18 years old and \< 65 years old 3. Normal colonoscopy or sigmoidoscopy 4. Negative celiac serologic markers 5. Normal complete blood count (CBC) and stool exam and stool culture 6. The patient should not be administered Anti-inflammatory drugs such as Nonsteroidal Antiinflammatory Drugs(NSAIDs), oral or parenteral Antibiotics, Corticosteroids, Mast cell stabilizers, Narcotics, Antidepressants and Immunosuppressive Agents. 7. Normal thyroid-stimulating hormone (TSH ) 8. Normal Serum Calcium 9. Educated patient Exclusion Criteria: 1. Breast feeding and Pregnancy 2. Presence of acute or chronic inflammation which can change the basal level of cytokines 3. Allergic disorders like Asthma (family and personal history) 4. Presence of organic disease like Diabetes mellitus or Psychiatric disorders. 5. Alcohol dependency and addiction to Tobacco and Opium 6. Patients who do not use efficient contraception method 7. History of extensive abdominopelvic surgery except Appendectomy, Cholecystectomy, Hysterectomy and Cesarian-Section 8. Presence of Celiac disease 9. History of Crohn's disease, Ulcerative Colitis and Diverticulitis during the previous year. 10. History of Cardiac, Pulmonary, Hepatic and Renal disease 11. Presence of chronic GI disorders 12. History of Allergy to Aspirin, Mesalamine or Sulpha compounds 13. History of Lymphocytic or Microscopic Colitis 14. History of significant weight loss ( 10% of body weight during 6 months), nocturnal sweating, GI bleeding and family history of Colon cancer 15. Patients with Lactose intolerance disease 16. Presence of Bowel Acid Malabsorption