Located in the female peritoneal cavity, the Pouch of Douglas plays a role in draining fluid from that area. Also known as the recto-uterine pouch, this part of the female anatomy also has important implications in peritoneal dialysis and the digestive system.
The recto-uterine pouch of Douglas is actually an extension of the peritoneum which lies between the posterior wall of the uterus and the rectum in females only; its male equivalent is the rectovesical pouch. The retro-uterine pouch, when referred to as the Pouch of Douglas refers to the Scottish anatomist, James Douglas who first identified the structure. It is the most dependent and lowest area of the peritoneal cavity in females.
The main function of the recto-uterine pouch is to aid in draining fluid from the peritoneal region, specifically that which normally occurs during menstruation. As such, low levels of fluid (between 1 and 5 milliliters) in the pouch throughout the menstrual cycle are considered normal. Higher levels may indicate conditions such as a ruptured ovarian cyst, peritonitis, a pelvic abscess or endometriosis.
In addition to its anatomical function, the recto-uterine pouch plays an important role in peritoneal dialysis, used for the management of end stage kidney failure. In this case, a catheter is inserted through the pouch into the peritoneal cavity and serves as a port for dialysate fluid and as a conduit for drainage.