The absence of a dark area of fluid in the rectal fossa of the uterus indicates that it is a normal phenomenon. Because the dark area of fluid in the rectal fossa of the uterus represents an exudate caused by chronic inflammation over a long period of time, when it is not present, there is no inflammation of the pelvis. When ovulation is judged, because after the follicle, the follicular fluid will flow to the pelvic cavity, then the absence of a dark area of fluid in the rectal fossa of the uterus indicates that the follicle has not ruptured or the follicle has atrophied. At this point, hormonal tests should be performed to rule out any other abnormalities. It is important to pay as much attention as possible to personal hygiene to avoid any upstream infection. When vaginal inflammation is present, prompt treatment should be given to avoid the presence of a dark area of fluid in the rectal fossa due to inflammatory stimulation.