The ligament of Treitz is commonly understood to be the suspensory ligament of the duodenum. It arises from the connective tissue around the stems of the celiac trunk and superior mesenteric artery and inserts into the third and fourth portions of the duodenum and frequently into the duodenojejunal flexure as well. It is an important anatomical landmark and used to divide the GI tract into an upper portion and a lower portion.