This study is for adults with Ulcerative Colitis (UC) or Crohn's Disease (CD). These are long-term illnesses causing symptoms like diarrhea, inflammation (swelling), bleeding, and belly pain. The study will test a drug called **Vedolizumab** to see if it helps make these symptoms go away after 3.5 months (14 weeks). Participants will be treated for about a year (50 weeks). For the first 1.5 months (6 weeks), they get Vedolizumab through a vein (intravenous). After that, they receive it as a shot under the skin (subcutaneous). If the treatment doesn't work after 3.5 months, participants can switch to another treatment. There are important check-ups at 6 months (26 weeks) and 1 year (52 weeks).

• The study lasts for about 1 year, with several clinic visits.
• Participants must be between 18 to 80 years old and meet certain health criteria.
• If the treatment doesn't work after 3.5 months, participants can switch to another treatment.