This is a multi-center, randomized, double-blind, placebo-controlled, parallel-design, dose-ranging study. Eligible patients with a DAI score of 6 to 10 (inclusive), plus endoscopic evidence of moderate to severe ulcerative colitis as assessed by flexible sigmoidoscopy, unless colonoscopy is clinically indicated, and rectal bleeding will be randomized to placebo or one of four doses of COLAL-PRED (equivalent to 40, 60, 80, or 120 mg of prednisolone). The effectiveness and safety of COLAL-PRED will be evaluated at baseline, and after 2 weeks and 4 weeks of treatment. Additional follow-up measurements will take place 7 days post cessation of treatment.