Ulcerative colitis (UC) is a chronic inflammatory bowel disease which often results in significant morbidity as well as impairment in quality of life. Cimzia (certolizumab pegol), an inhibitor of tumor necrosis factor-alpha, is an effective treatment for Crohn's disease, a similar inflammatory bowel disease. The aims of this study are to determine if Cimzia is effective for both the induction and maintenance of response/remission for the patients with moderate to severe Ulcerative colitis.