INSIGHT-IBD Pragmatic Study

The goal of this study is to evaluate the real-world effectiveness of treatments for inflammatory bowel disease (IBD) within routine clinical practice. The study population includes adult patients (≥21 years) with ulcerative colitis (UC) or Crohn's disease (CD) receiving care in community gastroenterology practices in the United States. The main questions it aims to answer are: * Does treatment with mirikizumab reduce the proportion of patients requiring an increase in IBD disease management (e.g., unplanned visits, dose escalation, therapy switch, emergency department visits, or hospitalization)? * Does treatment with mirikizumab improve clinical outcomes, including disease activity, clinical remission, and patient-reported outcomes, compared to standard biologic therapy? * Researchers will compare patients treated with mirikizumab within the IBD Clinical Care Pathway versus patients receiving standard biologic therapies to see if mirikizumab leads to improved disease control and reduced healthcare utilization. Participants will: * Receive either mirikizumab or standard biologic therapy as part of routine clinical care * Attend follow-up visits at approximately 3, 6, 12, and 18 months * Have clinical data collected from electronic health records and healthcare utilization sources * Complete patient-reported outcome questionnaires assessing symptoms, quality of life, and daily functioning * Undergo routine laboratory tests and clinical assessments as part of standard care

Inclusion Criteria: * Age ≥21 years at the time of enrollment * Confirmed diagnosis of ulcerative colitis (UC) or Crohn's disease (CD) * Eligible for treatment with biologic therapy for IBD, defined as failure of prior conventional therapy and/or prior biologic therapy (excluding IL-23p19 antagonists) * No prior exposure to mirikizumab and no contraindications to mirikizumab * Ability to provide informed consent * Willingness to comply with study procedures and follow-up requirements Exclusion Criteria: * Prior exposure to IL-23p19 antagonists (e.g., mirikizumab, risankizumab, guselkumab) * Prior exposure to small molecule targeted therapies for IBD (e.g., JAK inhibitors or S1P receptor modulators) * Participation in an interventional clinical trial within 90 days prior to enrollment * History of extensive colorectal resection, including: * Total proctocolectomy (for UC), or * Surgical removal of two or more intestinal segments (for CD) * Any condition that, in the investigator's judgment, may compromise patient safety, data integrity, or ability to participate in the study