Fun fact you might not be aware of if you are not the owner of a uterus: Periods go hand-in-hand with pooping. Not every person who gets a period will end up with diarrhea, but it’s not uncommon because the same hormone that makes a uterus contract (a necessary step in the whole period process) can also end up making your intestines contract. Francie Diep explains this effect — as well as the other hormone-related reason why periods and poops can be linked.