Background: Crohn’s disease in adolescents may present diagnostic and therapeutic challenges, particularly when small bowel involvement limits histological confirmation. Immunosuppressive treatment may also increase susceptibility to severe infections, including the uncommon complication of Campylobacter bacteremia.

Case Presentation: We report the case of a 13-year-old girl with Crohn’s disease diagnosed based on clinical and magnetic resonance enterography findings despite initially inconclusive histology. While receiving infliximab and azathioprine, she was admitted with fever and diarrhea. A gastrointestinal multiplex PCR assay was positive for Campylobacter, and blood cultures subsequently isolated Campylobacter jejuni. She was successfully treated with ciprofloxacin. Six months later, persistent small bowel stenosis required surgical resection. Histopathological examination of the surgical specimen revealed chronic active jejunitis with morphological findings consistent with Crohn’s disease. The patient subsequently achieved clinical stability on infliximab therapy.

Conclusion: This case highlights the diagnostic complexity of small bowel Crohn’s disease in adolescents and the importance of imaging when histological confirmation is initially unavailable. It also emphasizes that C. jejuni bacteremia, although uncommon, should be considered in immunocompromised patients with Crohn’s disease presenting with fever, with or without gastrointestinal symptoms. Early recognition and appropriate antimicrobial treatment are essential for a favorable outcome.