Classically, the ligament of Treitz is described as supporting and anchoring the duodenum, maintaining the position of the duodenojejunal flexure, and assisting in the movement of intestinal contents along the gastrointestinal tract.[2] It is generally understood to contribute to duodenal motility by elevating the duodenum and facilitating the passage of chyme into the jejunum.[3] 

More recent findings suggest that the ligament’s functional role may be more dynamic than purely structural. Rather than acting as a rigid suspensory structure, it may function as an extension of the diaphragm, transmitting diaphragmatic motion to the duodenum during respiration.[1] As the diaphragm contracts and relaxes with breathing, the ligament moves synchronously, producing subtle vertical motion of the duodenojejunal junction that may aid intestinal motility. 

Clinically, the ligament of Treitz remains an important anatomical landmark despite these evolving interpretations. It is used to distinguish upper from lower gastrointestinal bleeding and serves as a reference point in abdominal surgery and radiologic assessment. Notably, studies demonstrate that the ligament cannot be reliably identified on abdominal CT imaging and does not consistently prevent duodenal displacement by extrinsic masses, suggesting that some traditional textbook depictions may overstate its mechanical role.[1] Nevertheless, its anatomical and diagnostic significance remains well established.