Duodenojejunal flexure
Flexura duodenojejunalis
- Synonym: Duodenojejunal junction
Definition
The duodenojejunal flexure (DJ flexure) is the sharp bend between the ascending (fourth) part of the duodenum and the jejunum. It is located in the left upper quadrant of the abdomen, approximately 2.5 cm to the left of the midline, at the level of the L2 vertebra.
The duodenojejunal flexure is suspended and supported by the suspensory muscle of the duodenum (ligament of Treitz), a fibromuscular structure that extends from the right crus of the diaphragm to the duodenojejunal junction. Contraction of this muscle helps maintain the angle of the flexure and may assist the passage of intestinal contents from the duodenum into the jejunum.
The duodenojejunal flexure represents an important anatomical transition point between the retroperitoneal duodenum and the intraperitoneal jejunum.
References
Omole AE, Gogna S, KhorasaniZadeh A. Anatomy, Abdomen and Pelvis: Duodenum. [Updated 2026 Jan 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482390/
Standring, S. (2015) Grays Anatomy: The Anatomical Basis of Clinical Practice. 41st edn. London: Churchill Livingstone Elsevier. Chapter 65, Small intestine.
Ocasio Quinones GA, Woolf A. Duodenal Ulcer. [Updated 2023 Apr 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557390/
