Spondyloarthritis (SpA) is among the most frequent extra-intestinal manifestations in inflammatory bowel diseases (IBD). In this study, we aimed to validate the DETection of Arthritis in Inflammatory bowel diseases (DETAIL) questionnaire in a multicenter cohort of IBD patients enrolled at eleven Gastroenterology Units.From October 2018 to March 2019, consecutive adult patients with IBD, either Crohn's disease or ulcerative colitis, filled out independently the DETAIL in the outpatient waiting room. Within two weeks a blinded rheumatologist assessed all the patients, irrespectively of the DETAIL results, and classified them to be affected or not by SpA. The performance of the items was evaluated trough Bayesian analysis.Overall, 418 IBD patients filled out the DETAIL questionnaire. Upon rheumatological evaluation, 102 (24.4%) patients received a diagnosis of SpA. Of the six questions, the best performances were found in item 6 (LR+ 3.77), reporting inflammatory back pain at night, and in item 3 (LR+ 3.31), exploring Achilles enthesitis. The presence of back pain lasting more than three months (LR+ 2.91), of back pain with inflammatory features (LR+ 2.55) and a history of dactylitis (LR+ 2.55), showed also a fairly good performance, whereas a history of peripheral synovitis was slightly worse (LR+ 2.16). The combination of at least three items answered affirmatively yields a post-test probability of SpA of 80% or more. The presence of alternative diagnoses, such as osteoarthritis or fibromyalgia, represented a minor confounder.The DETAIL questionnaire is a useful tool for the early detection of SpA in IBD.