Comparison of the Efficacy of Different Biologic Agents in Preventing Postoperative Endoscopic Recurrence of Crohn's Disease

Inclusion Criteria: * Age ≥18 years. * Diagnosis of Crohn's disease according to the European Crohn's and Colitis Organisation (ECCO) guideline criteria, based on clinical, laboratory, endoscopic, radiologic, and histopathologic findings. * Underwent Crohn's disease-related intestinal resection, including ileocolonic resection, segmental small bowel resection, or segmental colonic resection. * Initiated postoperative prophylactic biologic therapy within 6 weeks after surgery. * Maintained postoperative prophylactic biologic therapy for at least 3 to 6 months. * Completed at least one evaluable postoperative ileocolonoscopy within 6 to 12 months after surgery for assessment of the Rutgeerts score, or had available clinical, radiologic, ultrasonographic, or laboratory data for evaluation of clinical recurrence. Exclusion Criteria: * Diagnosis of other intestinal diseases, including intestinal Behçet's disease, ulcerative colitis, intestinal tuberculosis, or intestinal malignancy. * Intestinal surgery mainly performed for non-IBD conditions, such as intestinal malignancy. * No postoperative endoscopic evaluation within 6 to 12 months after surgery, or endoscopic quality insufficient for Rutgeerts score assessment, and lack of adequate clinical, radiologic, ultrasonographic, or laboratory data for recurrence assessment. * Irregular use of postoperative prophylactic therapy due to severe comorbidities, serious infection, or other reasons, making treatment efficacy difficult to evaluate. * Other conditions considered by the investigators to be inappropriate for inclusion.