SummaryThe authors describe the normal anatomy of splanchnic arteries and of anastomoses between celiac trunk and superior mesenteric artery, as well as between superior and inferior mesenteric arteries.Blood flow may be diverted into one of these dilated anastomoses, possibly in the direction opposed to ordinary flow when resistance is increased in one of the main arteries (stenosis or thrombosis).Although increased collateral circulation may lead to suspect stenosis, these patients do generally not complain of abdominal pain, contrasting with patients with arterial stenosis hut without collateral circulation.Eight cases of stenosis of splanchnic vessels are documented.