The authors present a case of a Latin American patient with systemic lupus erythematosus who was referred for a mesenteric arteriogram because of acute lower gastrointestinal bleeding. Multiple segments of dilation alternating with stenosis or spasm were noted in the superior mesenteric artery/inferior mesenteric artery distributions. At the time, these irregularities were thought to be representative of lupus vasculitis. Despite appropriate treatment for vasculitis, the patient continued to have bleeding episodes and ultimately died of multiple organ failure. Autopsy demonstrated no evidence of vasculitis, but did demonstrate the unexpected finding of Strongyloides stercoralis hyperinfection with vessel invasion.