I have stomach pains that are getting worse than severe?

well for 2 weeks ive been taking these vitamin things called bagovit or somthing.i think its that that is giving me such severe stomach pains.i cant take the pain anymore :'[ theyr really strong theyr starting to make me cry of painfulness.i went out of contry to mexico.i didnt get sick overthere.but here since i started to take the medicine its makeing me get really strong stomach pains,and the only way theyll go away is going to the bathroom.in 1 hour, i was in the bathroom 2xs.1 x i was in the bathroom for about 10 minutes, the other time for 30 minutes.i cant stand the pain anymoree.im 14 so i dont know what to do,and my parents arent letting me stop taking the medicine they watch me until i swallow the pill so i cant lie about it.pleee helpppp