Hey Shoeless,
I have had similar situations at school (university). I think that it is best not to get worked up about it, and just roll with what comes at you. Like if some people are laughing or saying "there he goes again" I would just sort of join in and joke about it also, or just say something like what can I do with a smile. I do not think people laugh at you trying to be mean, and they likely do not realize that it can hurt you when they say or do those things.
Just focus on what you need to do (which may include runs to the bathroom) and do not focus any energy on what others think. You can not do anything about what they think, so it is not even worth worrying or bothering with.
Hope you can make it home soon, as just looking forward to getting home was what usually kept me going throughout the day.