Vedolizumab is a medication used in this clinical trial to evaluate its long-term safety in children with ulcerative colitis or Crohn’s disease. It is given through an intravenous infusion, which means it is administered directly into a vein. Vedolizumab works by targeting specific proteins in the body to help reduce inflammation in the gut, which can help manage symptoms of these conditions.

Ulcerative Colitis – Ulcerative colitis is a chronic inflammatory condition affecting the colon and rectum. It is characterized by continuous inflammation of the innermost lining of the large intestine, leading to symptoms such as abdominal pain, diarrhea, and rectal bleeding. The disease often progresses with periods of remission and flare-ups, where symptoms can become more severe. Over time, the inflammation can cause ulcers to form on the colon lining, potentially leading to complications like anemia or dehydration. The exact cause of ulcerative colitis is not fully understood, but it is believed to involve an abnormal immune response.

Crohn’s Disease – Crohn’s disease is a chronic inflammatory bowel disease that can affect any part of the gastrointestinal tract, from the mouth to the anus. It is characterized by patchy areas of inflammation, which can penetrate deep into the layers of the bowel wall. Symptoms often include abdominal pain, diarrhea, weight loss, and fatigue. The disease can progress with periods of remission and exacerbation, where symptoms worsen. Over time, Crohn’s disease can lead to complications such as strictures, fistulas, and malnutrition. The exact cause is unknown, but it is thought to involve a combination of genetic, environmental, and immune factors.