“…These include vasculitis of the retina (26,28,36), brain (19,23,30,34), skin (20‐22,24,33,39,40,45,50,51), muscle (25,29,44), joints (25,42,52) and lung (27,31,37,53). Moreover, the observation of antineutrophil cytoplasmic antibodies (ANCA) in some patients with UC and CD (usually perinuclear and directed against mixed epitopes) further lends credence to the hypothesis that a small vessel vasculitis could be a prominent pathogenetic mechanism in IBD (38,43,54,55).…”