Tunnel vision: rethinking local therapy for perianal fistulas in Crohn's disease A fistula is an abnormal tunnel or connection between two body parts that shouldn't be connected, like an organ and the skin or two organs, often forming after infection or inflammation ( View of Recent developments in the surgical management of perianal fistula for Crohn's disease Annals of Gastroenterology Is modern management of fistula in ano acceptable? British Journal of Hospital Medicine Modern management of perianal fistulas in Crohn's disease: future directions Gut