My daughter was sick last week in the hotel, poor thing. First she got the back to school cold which didn't manifest until day 2, so we took it easy. But later on in the week she ate imitation krab for the first time and I'm pretty sure that's why she was sick later that night. However, I had brought ibuprofen, allergy med, Pepto, Lactaid and various band-aids in a pseudo medical bag knowing how much hotels charge for that stuff. (I also brought a room spray and Poopourri because I know my tummy would not be good with theme park food) Sadly, she took the Pepto just to make herself vomit. She was feeling better by morning, at least.
It's like when I tell my kids to bring their umbrellas to school. If they don't bring it, it will rain. If they do bring it, it won't rain. It's the universe giggling at us.