Orphan patients with inflammatory bowel disease - when we treat beyond evidence.

Inflammatory bowel disease (IBD) is a chronic condition that requires continuous medical treatment. To date, the medical management of patients with moderately-to-severely active IBD who develop dependence or resistance to corticosteroids is based on immunomodulator drugs. Such therapies are licenced after passing through three phases of randomized controlled trials (RCTs), and are subsequently adopted in clinical practice. However, the real-life population of IBD patients who require these therapies can significantly differ from those included in RCTs. As a matter of fact, there is a number of exclusion criteria - nearly ubiquitous in all RCTs - that prevent the enrolment of specific patients: Chronic refractory pouchitis or isolated proctitis in ulcerative colitis, short-bowel syndrome and stomas in Crohn's disease, ileorectal anastomosis in both ulcerative colitis and Crohn's disease, and elderly age are some representative examples. In this frontier article, we aim to give an overview of current literature on this topic, in order to address the main knowledge gaps that need to be filled in the upcoming years.