A Guide Through the Tunnel: Updates in the Approach to Classification and Management of Perianal Fistulizing Crohn's Disease.

Purpose of review: Perianal fistulizing Crohn's disease (PFCD) is a severe and debilitating phenotype of Crohn's disease that presents significant clinical and therapeutic challenges. This review aims to outline a practical approach to classification and management, emphasizing the utility of the TOpClass system.

Recent findings: The TOpClass classification incorporates clinical and anatomic characteristics to assess severity, treatment options, and patient-clinician goals. Post-hoc analyses from clinical trials for the Janus kinase inhibitor Upadacitinib and emerging data on IL-23 receptor antagonists suggest potential roles beyond anti-TNFs, while the broader use of mesenchymal stem cell therapy remains limited due to inconsistent efficacy. Fistula conditioning with curettage and internal opening closure-an underutilized technique-alongside adjunctive therapies such as hyperbaric oxygen therapy (HBOT), has shown promise in promoting wound healing in select patients. The TOpClass classification, by integrating patient-centered factors and multidisciplinary management, offers a comprehensive and adaptable framework for PFCD, addressing key gaps in treatment planning, standardization, and research. The classification will enable tailored, evidence-based care across the disease spectrum.