Objective：To summarize the clinical and endoscopic features，as well as clinical outcomes，of patients with terminal ileum lesions，and to explore the diagnostic value of combining clinical and endoscopic features with changes in peripheral blood inflammatory markers for Crohn’s disease（CD），providing valuable evidence for clinical diagnosis and treatment. Methods：This study was a single - center retrospective study，including patients who underwent colonoscopy between January 2014 and June 2021 at the First Affiliated Hospital of Nanjing Medical University，with ileal terminal lesions identified. General information，medical records， endoscopy and pathological reports of the patients were collected，and clinical and endoscopic characteristics and etiological diagnosis were statistically analyzed. The patients with CD and non-specific terminal ileum ulcer were screened，and the clinical and endoscopic characteristics and peripheral blood inflammatory markers of the two groups were compared. Results：A total of 956 patients with terminal ileal lesions were included，93 of whom had a clear diagnosis，including CD，intestinal tuberculosis，benign tumors， adenocarcinoma，etc.，425 were lost to follow -up，and another 438 patients with unknown causes. Among the patients with unknown diagnoses，293 underwent follow-up colonoscopy，and 182 of them showed disappearance of lesions. Finally，22 patients with CD and 73 patients with non-specific terminal ileal ulcer were screened out. Compared with the latter，patients with CD have a higher incidence of abdominal pain at initial diagnosis and are more likely to show endoscopic features of ileocecal valve involvement. Peripheral blood inflammatory markers such as platelet count，hemoglobin，albumin，platelet/lymphocyte ratio，and neutrophil/lymphocyte ratio，were found to be of certain value in assisting the diagnosis of CD. The combined diagnostic value of the five indicators demonstrated a higher，with an area under the curve of 0.83. Conclusion：Most terminal ileal lesions are non-specific benign lesions and have a good prognosis. For patients with terminal ileal lesions，especially ulcers，identified during initial colonoscopy，attention should be paid to their clinical symptoms and endoscopic characteristics，and combined with changes in peripheral blood inflammatory markers，which can assist in the etiological diagnosis of terminal ileum lesions.