Patients diagnosed with ulcerative colitis, moderately severe in nature based on CDAI score who have received treatment and are either resistant or intolerant of anti-tumor necrosis factor.
May receive the study drug compared to a placebo to show improvement in their symptoms

This is a double blind, placebo- controlled study to evaluate efficacy and safety of Etrolizumab compared with a placebo in the age range of 18-80 years old.