Suddenly, there is a gut injury, abdominal pain, unintentional weight loss and vomiting: Mesenteric ischemia. mechanisms in poor blood circulation, a blood clot lodged in an artery, spasms of insufficient blood flow forming in the superior mesenteric vein Mesenteric ischemia dilated small intestine with thinned walls characteristic of ischemia of the intestine due to thrombosis of the superior mesenteric vein. intestinal infarction with necrozant infection