Under normal circumstances, the vaginal bleeding time after miscarriage will not exceed 7 days, if there is brown discharge for more than 7 days, it may be caused by the following reasons: 1. poor uterine regeneration resulting in the failure to discharge the blood in the uterine cavity in time, so it may cause brown discharge. 2. it may be caused by infection, often accompanied by lower abdominal pain, and may also have back pain, after gynecological examination can be clearly diagnosed. 3. It is possible that there is still residual tissue in the uterus, so there will be brown discharge all the time. And clinically, there will be paroxysmal pain in the lower abdomen, which will be clearly diagnosed through ultrasound examination, and the brown discharge will be cleared as soon as possible after timely treatment according to the results.