Study of Effects and of Modifications in Apoptosis Regulators Observed After Stopping 5-ASA Treatment in Patients With Inactive Ulcerative Colitis

Inclusion Criteria: * Male or female, 18 years of age or older. * Ulcerative colitis described according to usual criteria, diagnosed for at least 1 year. * Oral maintenance treatment with 5-ASA only for at least 3 months with a dosage of 2 to 3 g/day. * Clinical remission for at least 3 months (Mayo Clinic score) and endoscopic remission (endoscopic score of Mayo Clinic) at inclusion. * Signed informed consent form. Exclusion Criteria: * Patients allergic to aspirin or salicylates derivatives * Patients taking the following treatments during the study will be excluded: corticosteroids (oral or rectal route), use of NSAID or Aspirin, any form of sulfasalazine, mesalazine or 4-ASA. * Patients with known significant hepatic or known function abnormalities and/or creatine clearance ≤ 80 ml/min. * Patients with history or physical examination findings indicative of active alcohol or drug abuse. * Women who are pregnant or nursing. * Patients with a history of disease, including mental/emotional disorder that would interfere with their participation in the study. * Patients who participated in another clinical study in the last 3 months. * Patients who are unable to comply with the requirements of the protocol * Female of childbearing potential without efficacious contraception.