This retrospective cohort study aims to compare the efficacy of different biologics in preventing postoperative endoscopic recurrence in Crohn's disease (CD). It plans to include 198 adult patients who underwent bowel resection and initiated prophylactic biologic therapy between January 1, 2015, and April 1, 2025. Patients will be divided into anti-TNF (e.g., infliximab, adalimumab) and non-anti-TNF (e.g., vedolizumab, ustekinumab) groups based on the biologic started within 6 weeks post-surgery. The primary outcome is endoscopic recurrence (Rutgeerts score ≥ i2) at 6-12 months postoperatively. Secondary outcomes include severe endoscopic recurrence, clinical recurrence, recurrence at different anastomotic sites, CD-related rehospitalization, reoperation, drug persistence, the POCER postoperative endoscopic index, and histopathological changes in the bowel and mesenteric fat. Subgroup analyses will explore treatment effects by recurrence risk stratification and resection extent. Using retrospective data collection, the study will apply multivariate regression and survival analysis to provide real-world evidence for optimizing postoperative biologic selection.

This study is a retrospective cohort study aiming to compare the efficacy of different biologics in preventing endoscopic recurrence after surgery for Crohn's disease (CD). It plans to include 198 adult CD patients who underwent intestinal resection and initiated prophylactic biologic therapy between January 1, 2015, and April 1, 2025. Patients will be divided into an anti-TNF group (e.g., infliximab, adalimumab) and a non-anti-TNF group (e.g., vedolizumab, ustekinumab) based on the biologic agent used within six weeks post-surgery. The primary outcome is the rate of endoscopic recurrence (Rutgeerts score ≥ i2) at 6-12 months postoperatively. Secondary outcomes include the rate of severe endoscopic recurrence, clinical recurrence, recurrence at different anastomotic sites, CD-related rehospitalization, reoperation, drug persistence, the POCER postoperative endoscopic index, and pathological changes in the intestinal tissue and mesenteric fat. Subgroup analyses will be conducted to explore differences in efficacy across varying levels of recurrence risk and resection extent. Through retrospective data collection and statistical analyses including multivariate regression and survival analysis, this study aims to provide real-world evidence to optimize the selection of postoperative biologic therapy in clinical practice.

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.

This retrospective cohort study will include adult patients with Crohn's disease who underwent CD-related intestinal resection at Shanghai Tenth People's Hospital between January 1, 2015 and April 1, 2025. Eligible patients initiated postoperative prophylactic biologic therapy within 6 weeks after surgery and had available postoperative follow-up data, including endoscopic assessment within 6 to 12 months after surgery or other clinical data for recurrence evaluation. Patients will be grouped according to the type of postoperative prophylactic biologic therapy, including anti-TNF biologics and non-anti-TNF biologics.