I initially assumed that I had been eating poorly, or that my stomach had somehow become more sensitive than normal. You know, accomplished and all that Black women shitting girls pooping. This makes the uterus contract more strongly. These are the chemical signals girls' and women's bodies make and send to the uterus to tell it to contract, thus expelling the uterine lining at the end of the menstrual cycle. Nevertheless, a woman taking birth control may still feel some gastrointestinal effects just before her "period. That also means the prostaglandins aren't at work making women poop.