Body Composition Assessment and Monitoring in Inflammatory Bowel Disease

This is a single-center, prospective observational study aiming to describe changes in body composition (specifically, percentage of lean mass and phase angle) in patients with active inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease. The study will recruit patients with a confirmed IBD diagnosis who are starting biologic therapy or Janus kinase inhibitors (JAKi) to induce clinical remission. Body composition will be assessed using bioelectrical impedance analysis (BIA) at baseline (time 0), 24 weeks, and 52 weeks after starting medication. Clinical disease activity, endoscopic findings, and laboratory data will also be collected at various time points if available. The study has a total duration of 36 months, including a 12-18 month patient inclusion period and a 12-month follow-up. Patients will provide informed consent, and all treatment decisions will follow standard clinical practice, as this is a non-interventional observational study.