Gastrointestinal (GI) manifestations of systemic vasculitides (SVs) are a challenge for the clinician because of the variety and severity, since acute or chronic course can be observed. Importantly, no vessel size can be ruled out in any of the commonly classified inflammatory vasculitides. Acute intestinal vasculitis presents as a rapidly evolving disease with intensive abdominal pain, followed by signs of peritonitis and ileus, and may progress into a life-threatening shock syndrome with high mortality. Even if chronic vascular diseases are related to arteriosclerosis in more than 90% of patients, in the remaining 10% of patients, they may be due to chronic intestinal vasculitides. Chronic intestinal vasculitides are associated with important morbidity and mortality, and they can mimic all types of GI disorders; thus, a diagnostic workup should be performed starting from patient's history. Novel diagnostic tools and therapeutic strategies can help the clinician better manage vasculitides in general, and the GI involvement, in particular
