Dude, don't worry about people being afraid of your stomach problems. If they are cool people, they won't care. My man saw my medicine cabinet and could have absolutely freaked, but he waited until I started talking about it before asking me anything, and he's been by my side ever since.
I find that tequila works for me as well : ) Imodium is a blessing at the bar. Double up, but don't be surprised if you don't go for the entire next day. Drink plenty of water. If you use the bathroom, try some courtesy flushes : ) Don't get yourself in a tizzy because it will make you worse. Just go and have fun and if you have to go to the crapper, so be it!!