<h3>Background</h3> Time trend studies have shown a rising incidence and prevalence of inflammatory bowel diseases (IBD) in China. IBD is a complex disease, which can present with a large number of extraintestinal manifestations (EIMs), such as skin, eye and joint lesions. Among these EIMs, spinal involvement is often silent and do not correlate with IBD activity. So the prevalence of spinal involvement in IBD is poorly understood. <h3>Objectives</h3> To estimate the incidence of sacroiliitis and other extraintestinal complaints among patients with IBD in Tianjin Union Medical Centre. <h3>Methods</h3> From September 2017 to January 2018, for all patients who came to our hospital do endoscopic examination, we picked out patients who had a diagnosis of IBD (include ulcerative colitis, crohn`s disease and colitis). All IBD patients who agreed to participate in the study completed a questionnaire. To investigate the incidence of spondyloarthritis, part of patients took screening test. Radiologic examination of pelvic to screen sacroiliitis, blood sample to test erythrocyte sedimentation(ESR), C-reactive protein(CRP) and human leukocyte antigen B27 (HLA-B<sub>27</sub>). <h3>Results</h3> 87 patients were enrolled; 93.1% had ulcerative colitis (UC), 1.1% had Crohn’s disease (CD), and 5.7% had colitis. Among them, 54% were female. The mean age of onset in female and male was 47.6 years (range from 28 to 81) and 41.3 years (range from 18 to 72) respectively. Of the 87 patients, 56 patients (64.4%) had a history of articular pain, some of which were involved in axial articular (45/56), peripheral articular (2/56), and both axial and peripheral articular (9/56). 20 patients (22.98%) had history of enthesitis (e.g. plantar fasciitis, tendinitis achillea, anterior chest wall pain). 4 patients (4.6%) had history of skin impairment (e.g. nodule erythema, psoriasis, uticaria). 6 patients (6.9%) had history of ocular lesions (e.g. red eye, sore eye, epipephysitis, cataract, vitreous opacity). 5 patients (5.7%) had oral ulcer. 3 patients had family history of gastrointestinal disease (2 bowel cancer,1 UC). 25 patients conducted radiologic examination of pelvic (14 X-ray, 10 CTs and 1 MR). 8 patients (32%) revealed sacroiliitis. Among these 8 patients, 2 of them showed asymptomatic radiological involvement of sacroiliac joint. The texts of HLA-B<sub>27</sub> were performed in 29 patients (include patients who conducted radiologic examination of peivic), and all revealed negative results. 52 patients tested ESR and CRP, 30 patients showed higher results than normal bias. <h3>Conclusions</h3> This study displayed the incidence of sacroiliitis, among patients with IBD in our centre, it showed that patients with IBD have a higher incidence of sacroiliitis. In order to evaluate the patients comprehensively, IBD patients with articular pain should be evaluated by rheumatologist. Besides, among our patients with IBD, the occurance of HLA-B<sub>27</sub> is low, and there were no correlation between IBD activity and articular symptoms or inflammatory indicators. <h3>Reference</h3> [1] inflammatory bowel disease, extraintestinal manifestations, sacroiliitis <h3>Disclosure of Interest</h3> None declared