First date and dirreah ....what to do???

i met a new guy and we are going out for drinks. i have to drink on the first date or i will be a nervous wreck. all i can drink are "pile drivers" ...that's prune juice and vodka. i can't drink beer, wine, or any other liquors or washes. pile drives really cleanse a person out. is there anything i can take to avoid the hershey squirts? AD imodium and pepto don't work...any other suggestions?? thanks.