Eligibility Criteria:
Inclusion Criteria:
* Signed informed consent,
* Men or women aged 18 to 75 years,
* Active ulcerative colitis, except proctitis limited to 15 cm ab ano, confirmed by endoscopy and histology,
* Established disease,
Exclusion Criteria:
* Crohn's disease, indeterminate colitis, ischaemic colitis, radiation colitis, microscopic colitis (i.e., collagenous colitis and lymphocytic colitis, incomplete microscopic colitis), diverticular disease associated colitis,
* Toxic megacolon or fulminant colitis,
* Colon resection,
* Evidence of infectious colitis (e.g., pathogenic bacteria or Clostridium difficile toxin in stool culture at screening),
* Malabsorption syndromes,
* Celiac disease,
* Bleeding hemorrhoids,
* Active peptic ulcer disease
* Other inflammatory or bleeding disorders of the colon and intestine, or diseases that may cause diarrhea or gastrointestinal bleeding,
* Hypertension, diabetes mellitus, osteoporosis, peptic ulcer disease, glaucoma, cataract, or infection if careful medical monitoring is not ensured,
* Any severe infectious disease (e.g., tuberculosis, AIDS),
* Severe co-morbidity substantially reducing life expectancy,
* History of colorectal cancer,
* History of cancer (other than colorectal) in the last 5 years, except for basal cell carcinoma