Current practice and innovations in diagnosing perianal fistulizing Crohn's disease (pfCD): a narrative review.

Perianal fistulizing Crohn's disease (pfCD) represents a severe manifestation of Crohn's disease (CD) that often leads to significant morbidity. Clinical examination alone of perianal fistulae is unlikely to be sufficient in the context of complex pfCD, as patients are likely to have complex disease and are more likely to experience complications, treatment failure, and recurrent disease. Furthermore, the relapsing-remitting nature of Crohn's disease and our limited understanding of the pathogenesis of this potentially destructive disease necessitate regular examination and radiological assessment, often in the form of magnetic resonance imaging (MRI). Recent advancements in diagnostic techniques have enhanced the accuracy and timeliness of pfCD diagnosis, facilitating better patient outcomes. A growing appreciation of isolated perianal Crohn's disease has prompted a recent attempt to develop consensus recommendations on diagnosing and treating this group of patients who would previously not have been offered CD medications. This narrative review aims to summarize current practice and the latest developments in the diagnosis of pfCD, highlighting: 1. Clinical examination and assessment tools 2. Current imaging practices 3. Innovations in imaging and biomarkers 4. The diagnosis of isolated perianal Crohn's disease.