PHASE: IV||TYPE OF STUDY: With direct benefit.||DESCRIPTIVE: Multicenter, randomized, open label study.||INCLUSION CRITERIA: Steroid-refractory ulcerative colitis.||OBJECTIVES: To compare the efficacy of cyclosporine with infliximab in steroid- refractory attacks of ulcerative colitis.||STUDY TREATMENTS:Cyclosporine 2mg/kg/day intravenous(IV)for 7days then Neoral 4mg/kg/day orally for 3 months. Infliximab 5mg/kg at Weeks 0, 2 and 6.||NUMBER OF PATIENTS: 50 patients in each group i.e. a total of 100 patients.||INCLUSION PERIOD: 24 months.||STUDY DURATION: 27 months.||MAIN EVALUATION CRITERIA:||Clinical response at D7 according to the Lichtiger Index score AND Clinical Remission at D98 according to the Mayo Disease Activity Index score||SECONDARY EVALUATION CRITERIA:||Clinical remission at D98 (according to the Mayo Disease Activity Index score) Endoscopic response Colectomy rate Tolerance