There are several reasons why there is brown residue after menstruation: 1. It may be because of gynecological inflammation, common endometritis, vaginitis, pelvic inflammatory disease and tubal inflammation, etc. Especially when you have endometritis and vaginitis, it is more likely to occur, because normal menstruation is formed by the regular contraction of small arteries of the uterine lining, and when there is inflammation in the endometrial lining it is easy to lead to the occurrence of the menstrual color and character of menstruation When there is inflammation of the endometrium, it tends to cause the color and character of menstruation to change, and the color of the discharge is different due to different bacterial infections. If you have vaginitis, it can also lead to brown residue after menstruation, the residue is the secretion of inflammation or necrotic tissue cells slowly discharged after slow menstruation. 2. For older women, if you suspect that there is tumor disease, such as endometrial cancer, cervical cancer, etc., the secretion of tumor, the shedding of tumor cells, necrosis, or ulcerations and erosions of the tumor local tissues, all of them can form brown residue, which can be seen after menstruation. 3. residue, which can only be seen after menstruation.