A separation of 3mm is usually cleared within a week and may take longer if there is an infection. Separation of the uterine cavity is a descriptive term after ultrasound examination, which often indicates that there is a residue in the uterine cavity that causes separation of the lining of the uterus in the anterior and posterior walls of the uterus. Currently, it is believed that separation of the uterine cavity is most commonly seen in incomplete shedding of the uterine lining after menstruation, residual embryonic tissue after miscarriage, and uterine effusion, with the main clinical manifestations being vaginal bleeding and vaginal fluid. Usually, after active treatment to promote uterine contraction to discharge the stagnant blood, a week time can be discharged. However, if the infection is combined, there is not only blood, there may even be pus oozing out, at this time, active anti-infection treatment is needed, at this time, the uterine cavity to separate the intrauterine blood and fluid discharge time will be prolonged.