"It is named after the Scottish anatomist James Douglas (1675–1742) 2."
"The rectouterine pouch (TA: excavatio rectouterina 3), also known as the rectovaginal pouch, cul-de-sac or pouch of Douglas, is an extension of peritoneum between the posterior wall of uterus and the rectum in females. It is the most dependent part of the peritoneal cavity and is analogous to the rectovesical pouch in males."
"Being the most dependent and lower area of the peritoneal cavity of females in the supine position, fluids (e.g. abscess, infection, ascites, haemoperitoneum, and even intraperitoneal drop metastases) preferentially collects here."