Introduction. Approaching the pediatric patient with joint pain is often a challenge, even for the most experienced clinicians. The diagnosis of inflammatory bowel disease in children may be difficult because of atypical symptoms and/or extraintestinal manifestations such as arthritis, weight loss, chronic anemia, unexplained fever. Case presentation. We present the case of a 13-year-old girl, presented initially with musculoskeletal complains, feverish, weight loss. After an extensive clinical and paraclinical examination and a proper differential diagnosis, the diagnosis of inflammatory bowel disease was established, confirmed by immunological investigations, colonoscopy with biopsy. The peculiarity of the clinical case translates into the onset of ulcerative colitis through extraintestinal manifestations, the main clinical manifestations being related to articular involvement. Conclusions. Overlap syndromes are a main challenge for clinicians. Inflammatory polyarticular syndrome in a child can often result in a benign self-limiting disease, but sometimes may reveal a serious chronic disease with significant morbidity. Ulcerative colitis diagnosed in children presenting with an amalgam of extraintestinal manifestations requires a multidisciplinary approach.