For the last 9 months or so I've been having diarrhea 1 week before my period and its horrible and sometimes I get it 2 times a month. I feel sick right after I eat that I have to go the the bathroom right away and than I poop. my stomach hurts really bad for like 2 days after that but that I feel completely fine. please someone help I need it. I'm sick of this. (could it be a allergy?)