Brown discharge two days before menstruation may be caused by abdominal cold, drug effects and endocrine disorders. 1. Cold abdomen: consuming a lot of cold food or catching a cold abdomen before menstruation may lead to early menstruation, but because of the poor circulation of menstrual blood, the volume of blood is reduced, thus appearing two days before menstruation with brown discharge. 2. Drug effects: withdrawal bleeding after taking emergency contraceptive pills two days before menstruation can also occur two days before menstruation with brown discharge. 3. Endocrine disorders: for example, luteal insufficiency, luteal insufficiency will make the level of estrogen and progesterone is relatively low, the endometrium loses the support of hormone levels, there will be irregular exfoliative bleeding, resulting in brown discharge two days before menstruation. Patients with symptoms of brown discharge two days before menstruation are advised to go to a regular hospital for timely examination and standardized treatment to identify the cause.