Between the rectum and the bladder the peritoneal cavity forms, in the male, a pouch, the rectovesical excavation (or rectovesical pouch), the bottom of which is slightly below the level of the upper ends of the vesiculae seminalesbi. e. , about 7.5 cm. from the orifice of the anus. its lowest part membranous partition called Rectoprostatic fascia. The corresponding structure in women is the rectouterine pouch. [ http://en.wikipedia.org/wiki/Recto-vesical_pouch ]