The rectouterine pouch (or rectouterine excavation, rectovaginal, Ehrhardt-Cole Recess or Pouch of Douglas) is the extension of the peritoneal cavity between the rectum and back wall of the uterus in the female human body. The rectouterine pouch is used in the treatment of end-stage renal failure in patients who are treated by peritoneal dialysis. The tip of the dialysis catheter is placed into the deepest point of the pouch. In women it is the deepest point of the peritoneal cavity, posterior to (behind) the uterus and anterior to (in front of) rectum. (The pouch on the other side of the uterus is the vesicouterine excavation. ) It is near the posterior fornix of the vagina. In men, the region corresponding to the rectouterine pouch is the rectovesical excavation, which lies between the urinary bladder and rectum. (There is no equivalent to the vesicouterine excavation.). [ http://en.wikipedia.org/wiki/Recto-uterine_pouch ]