Background: Musculoskeletal involvement in inflammatory bowel disease (IBD) patients contributes to poorer outcomes and reduced quality of life (QoL). We aimed to describe the prevalence and distribution of peripheral and axial musculoskeletal symptoms and clinical findings in patients with IBD prior to biological treatment.

Methods: Bio-naïve patients with IBD were consecutively recruited. Musculoskeletal symptoms were assessed using questionnaires and a structured interview. A rheumatologist conducted a clinical evaluation of peripheral joints and entheses, spine mobility, and considered various differential diagnoses.

Results: Of 82 patients (ulcerative colitis (UC): 33, Crohn's disease (CD): 49, mean age 46 years, 55% male), 51 (62.2%) had musculoskeletal symptoms and 51 (62.2%) had clinical findings. Peripheral joint pain was reported by 39 (47.6%) patients, entheseal pain by 15 (18.3%), and back pain by 33 (40.2%) patients. Clinical evaluation revealed arthritis in 24 (29%) patients and enthesitis in 50 (61%); enthesitis was asymptomatic in 72% of the cases. The Assessment of Spondyloarthritis international Society (ASAS) classification criteria for peripheral spondyloarthritis were met in 36 (44%) patients, and for fibromyalgia in 7 (8.5%) patients. Being female was associated with more frequent musculoskeletal symptoms and clinical findings. Significantly more patients with CD reported joint pain, but no differences in clinical findings were observed between UC and CD, nor between those with active and inactive IBD.

Conclusions: Two-thirds of patients with IBD scheduled for their first biological treatment exhibited musculoskeletal involvement, sometimes asymptomatically. Axial and peripheral symptoms were equally common. A multidisciplinary approach is crucial for early detection and integrated treatment aiming for remission in all disease domains to improve patients' QoL.