<prompt> Most common cause of acute mesenteric ischemia isAerial thrombosisVenous thrombosisEmbolismNon occlusive disease  <response>: .Superior mesenteric aery is commonly involved than inferior mesenteric aery. Often superior mesenteric vein can also get involved. Causes Embolism 50--Sources - From left auricle, as seen in atrial fibrillation. - A mural infarct. - Atheroma from aoa or aneurysm. - Endocarditis vegetations. - Left atrial myxoma. Thrombosis--may block the origin of the superior mesenteric aery and can cause ischaemia of full length of small bowel. It is life threatening. ref:SRB;s manual of surgery,ed 3,pg no 806 