Tacrolimus (FK506) P-III, Open-label Study in Refractory Ulcerative Colitis Patients

Inclusion Criteria: * Severe refractory UC patients who meets the following criteria * Disease activity: more than 6 times of stool a day, bloody stool, moderate to severe endoscopic finding * Steroid resistant or dependent OR * Moderate to severe refractory UC patients who participated and received placebo in F506-CL-1107 study Exclusion Criteria: * Mild or fulminant type * Renal failure patients, hepatic failure patients * Patients taking 6-mercaptopurine, cyclosporin or other immunosuppressants within 12 weeks prior to entry * Patients who received LCAP or GCAP within 2 weeks prior to entry * Patients who changed the dose of steroid or started steroid within 2 weeks prior to entry * Patients who changed the dose of steroid or started steroid within 1 week prior to entry in case they received more than 40 mg/ day or 1mg/kg/day of steroid just before the study