Endocopic remission rates of moderate to severe ulcerative colitis are low. Biologics including Vedolizumab, infliximab, and adalimumab are effective in induction and maintainence of ulcerative colitis. The role of 5-ASA in promoting a higher rate of endocsopic remission is unclear. We aim to evaluate the efficacy of combination of 5-ASA and biologics in treating ulcerative colitis.