Ischemic pseudomembranous colitis with perforation due to polyarteritis nodosa.

Polyarteritis nodosa is a multisystem disease that involves the gastrointestinal tract in more than 50% of patients at some time during its course. Clinically apparent ischemic disease of the small bowel is the frequent site of involvement. The colon is less commonly involved, particularly as the initial presentation. We present a patient with polyarteritis nodosa noteworthy for prolonged nonbloody diarrhea, ischemic colitis with perforation, and pseudomembrane formation who had histological documentation of polyarteritis nodosa.