Abstract
A 51-year-old woman with fever was admitted to our hospital. A computed tomography (CT) scan showed thickened colonic walls. Colonoscopy revealed erosion in the ileum and colon. Adult-onset Still's disease (AOSD) was diagnosed due to a subsequent sore throat and skin rash. Following AOSD treatment, methylprednisolone pulse therapy, followed by prednisolone and cyclosporine, was initiated. Despite achieving a temporary improvement, relapse occurred with fever, abdominal pain, with worsening CT and endoscopic findings. The reappearance of a skin rash confirmed an exacerbation of AOSD. Tocilizumab treatment alleviated the symptoms and improved the endoscopic findings. Considering their correlation with the symptoms and endoscopic findings, the observed gastrointestinal lesions may be linked to AOSD.