Millie
the same hormones that cause your uterus to contract to get rid of the lining also cause your gut to contrac and relax, hence you get diarrhea. you may need something that will help for constipation during the other times that will help loosen up those muscles. sometimes prozac or zoloft can help people. if you have stomach cramping at night, you may need a low dose tricyclic antidepressant to help with your quality of sleep like doxepin or amitriptyline. (low dose because high doses can worsen constipation)