Ulcerative Colitis (UC) and Crohn's Disease (CD) are illnesses that make the stomach and intestines hurt, causing diarrhea and bleeding. In this study, we want to see if the medicine Vedolizumab can help these problems go away after about 3.5 months (14 weeks). Participants will take Vedolizumab for about a year (50 weeks). At first, they will get the medicine through a needle in their vein (intravenous) for 6 weeks, and then through a shot under the skin (subcutaneous) for the rest of the time. If the medicine doesn’t help after 14 weeks, participants can try a different treatment. They will have extra check-ups at 6 months and 1 year and again after stopping the medicine. Participants need to visit the study clinic several times.

• Study lasts about 1 year with multiple clinic visits.
• Treatment changes if no improvement after 3.5 months.
• Must be 18-80 years old and meet health requirements to join.