Brown discharge on the underwear may occur when the menstruation is about to start or when it is about to end. In addition, if the patient bleeds during ovulation, brown discharge may also appear. For these two cases mentioned above, they are normal physiological phenomena and usually do not require special treatment or therapy. It can also be seen pathologically, for example, if the patient has endometrial polyps, inflammation of the cervix, inflammation of the vagina, inflammation of the endometrium, or diverticula with uterine scarring, ovarian tumors that secrete estrogen, etc., brown discharge on women’s underwear can occur. For these cases, patients need to go to the hospital for examination as soon as possible to clarify the diagnosis and the next treatment plan.