The possible causes of black stools during menstruation are: one is the presence of intestinal bleeding, and the other possibility is the influence of food or medication, resulting in the black color of stools. It is recommended to go to the regular hospital to do a routine examination of the stool, timely identification of the causes of symptomatic treatment. Usually in the diet to eat more fruits, vegetables, drink more water, to light, easy to digest, easy to absorb food. Oral iron supplements, animal liver, pig’s blood, sheep’s blood, etc. can also cause black stools. Make it a habit to defecate on time every day, eat more foods rich in vitamins and fiber, eat more celery, dragon fruit, kiwi and other laxative vegetables and fruits. Usually pay attention to pubic hygiene and cleanliness, wash underwear regularly and expose them to sunlight.