Mild nonocclusive mesenteric ischemia associated with syncope.

Nonocclusive mesenteric ischemia (NOMI) is a life-threatening disease caused by a reduction in mesenteric blood supply without vascular occlusion. Early diagnosis of NOMI is often difficult because there are no specific findings suggesting NOMI. Here, we report a rare case of a very elderly patient with mild NOMI caused by dehydration due to short-term reduced oral intake and associated with syncope. A 90-year-old man was admitted to our hospital with syncope and melena. The syncope was thought to be caused by orthostatic hypotension due to dehydration owing to reduced oral intake for approximately 24 h. Abdominal computed tomography (CT) revealed marked bowel wall thickening with mesenteric stranding in the ileum and ascending colon, dilated small intestine with thinned bowel wall, collapsed superior mesenteric vein, hemorrhagic ascites, and absence of obvious vascular occlusion in the mesenteric vessels. Abdominal symptoms, laboratory abnormalities, and CT findings improved gradually with the correction of dehydration. Therefore, we diagnosed our patient with mild NOMI. NOMI can be associated with syncope and can occur even with dehydration due to short-term reduced oral intake. When examining elderly patients with hypovolemic signs, such as syncope, who exhibit abdominal symptoms, clinicians must keep in mind the possibility of NOMI.