my girl told me of this pain she has had since she was 13 but it only accures every two years and only for about eighteen hours and then it gose away. it also causes her to need to pee altho she dosent need to,she sayes it feels like a pulling sensation in or around the belly button  every time she tryes  to straighten up laugh or walk or go to pee. dose anyone have a idea of wat it might be?