Identifying Outcomes in Clinical Trials of Fistulizing Crohn's Disease for the Development of a Core Outcome Set.

Fistulizing complications develop in approximately one third of patients with Crohn's disease (CD), resulting in morbidity and impaired quality of life.1 Sites of fistulae most commonly include perianal fistulae, but also enterocutaneous, enteroenteric, enterovesical, and rectovaginal. Its management requires combined medical and surgical strategies to prevent abscess formation and induce healing. Biologic agents have improved the medical treatment of CD-related fistulae, but many patients still require surgical intervention. Hence, there is considerable interest in the development of novel pharmaceutical agents to treat fistulizing CD.