Vedolizumab is primarily used in the treatment of inflammatory bowel diseases (IBD), including ulcerative colitis and Crohn's disease. It works by selectively targeting and inhibiting the interaction between specific integrins on immune cells and their receptors in the gastrointestinal tract, thereby reducing inflammation in the gut. This mechanism helps to alleviate symptoms such as abdominal pain, diarrhea, and rectal bleeding, and can induce and maintain remission in patients with moderate to severe IBD. Vedolizumab is particularly valued for its gut-specific action, which minimizes systemic side effects compared to broader immunosuppressive therapies. It is administered intravenously and is often considered for patients who have not responded well to other treatments like corticosteroids, immunomodulators, or anti-TNF agents.