What is douglas pouch and what does it mean if it contains fluids?

Pouch of Douglas: Is the peritoneal fold between the back wall of the uterus and front wall of rectum in women. It is the most dependent portion of the peritoneal cavity. When pelvic organs are inflamed or an ovarian cyst ruptures or bleeds, the reactive fluid, cyst fluid, or blood can collect here.

Anatomical location: Area located between uterus and rectum most dependent part, accessible area for examination, any pathological changes will gravitates to this location , like pus as in appendicitis, cancer cells as in ovarian or stomach or early fluid collection etc , easy to md to examine bimanually, of course with recent ct, sono etc , no need to under go painful examination.