 This is a long term, multicenter, international safety study to evaluate targeted long-term safety information on patients who have participated in infliximabRemicade clinical studies in ulcerative colitis that require long-term safety follow-up. All patients who received at least one dose of study drug infliximab or placebo in the primary studies C0168T37 ,C0168T46, C0168T72 are eligible to participate in this long-term safety follow-up study C0168T62. Patients will begin participation in C0168T62 at the time of their last safety visit in the primary study and will be followed for 5 years. No study agent will be administered. Information on deaths, serious infections, new malignancies including colorectal cancer and new autoimmune diseases and surgical procedures including colectomy and hospitalizations for the treatment of ulcerative colitis will be collected. Information about possible delayed allergic reactions possible fever, rash, fatigue, joint pain will also be collected if patients received infliximab after the end of the primary study. In addition, data on dysplasia of the colon will be collected from patients who were identified in the primary study to be at high-risk for colon cancer and were required per protocol to undergo a follow-up colonoscopy as part of long-term safety follow-up. All adverse events, including non-serious adverse events, will also be collected. 