Epidemiology of Extraintestinal Manifestations in Chinese Inflammatory Bowel Disease Patients: A Single-Center Retrospective Study

Background Inflammatory bowel disease (IBD) is frequently associated with various extraintestinal manifestations (EIMs) that significantly impact patient prognosis. While the incidence of IBD continues to rise in China, systematic research on the epidemiological characteristics of EIMs remains limited, particularly in the context of widespread biologic therapy use. This study aims to comprehensively characterize the epidemiological features of EIMs in Chinese IBD patients to inform clinical practice. Methods We conducted a retrospective analysis of 649 inpatients with IBD at Xijing Hospital between October 2020 and December 2024. EIMs were diagnosed using standardized clinical, imaging, and specialist criteria. We assessed prevalence, temporal patterns, and Associated factors through multivariate logistic regression. Results The overall EIMs prevalence was 37.3%, with CD patients showing higher rates than UC (42.9% vs. 34.4%, P = 0.034). Joint manifestations (21.2%) were most common, with UC patients exhibiting more arthritis/arthralgia (23.7% vs. 16.4%, P = 0.032), while CD patients had significantly higher rates of aphthous ulcer (28.8% vs. 8.4%, P < 0.001). Notably, when excluding aphthous ulcer, UC patients demonstrated higher overall EIMs prevalence (30.2% vs. 21.0%, P = 0.012). EIMs preceded intestinal symptoms in 17.8% of cases. Arthritis/arthralgia showed strong associations with sacroiliitis (OR = 12.3) and erythema nodosum (OR = 10.2). Multivariate analysis revealed female sex (OR = 1.6) and TNF antagonist use (OR = 2.0) as factors associated with EIMs in UC, while immunosuppressant use (OR = 2.5) was associated with EIMs in CD. Conclusions As an autoimmune disease with increasing incidence rate, the extraintestinal manifestations of IBD or the comorbidity of other autoimmune diseases, has not received sufficient attention in Chinese IBD patients. This study reports the prevalence of EIMs in IBD patients from a single Chinese center, demonstrating distinct patterns compared with Western populations. The observed higher prevalence of aphthous ulcer and arthritis/arthralgia may be attributed to the reliance on patient self-reports, which could lead to increased detection rates of these symptoms. The lower prevalence of certain diseases may be due to insufficient attention from patients and healthcare providers. Future nationwide multicenter studies are warranted to refine diagnostic approaches and improve EIMs awareness among Chinese IBD clinicians and patients.