Space
Rectouterine pouch (of Douglas)
A dependent peritoneal recess behind the uterus
High-yield
The posterior vaginal fornix is closely related to the rectouterine pouch. A small amount of free pelvic fluid can be physiological.
Overview
The rectouterine pouch lies between the uterus and upper vagina anteriorly and the rectum posteriorly. Its inferior extent approaches the posterior vaginal fornix. Fluid can collect in this dependent pelvic recess, although distribution also changes with posture and surrounding organs.
Reference facts
- Boundaries
- Between the posterior uterus/upper vagina and anterior rectum, with lateral rectouterine folds related to uterosacral tissues.
- Contents
- Normally contains a potential space and a small variable amount of fluid; mobile bowel may occupy the recess.
- Communications
- Continuous superiorly with the peritoneal cavity and adjacent pelvic recesses; separated from the posterior vaginal lumen by vaginal wall, connective tissue and peritoneum.
Clinical correlation
Blood, inflammatory fluid or malignant deposits may be found here, and endometriosis can affect the posterior pelvic compartment. Fluid or tenderness at this site must be interpreted in context rather than treated as proof of a ruptured ectopic pregnancy.
Frequently asked questions
What are the boundaries of the rectouterine pouch (of Douglas)?
Between the posterior uterus/upper vagina and anterior rectum, with lateral rectouterine folds related to uterosacral tissues.
What does the rectouterine pouch (of Douglas) contain?
Normally contains a potential space and a small variable amount of fluid; mobile bowel may occupy the recess.
What does the rectouterine pouch (of Douglas) communicate with?
Continuous superiorly with the peritoneal cavity and adjacent pelvic recesses; separated from the posterior vaginal lumen by vaginal wall, connective tissue and peritoneum.