So, for the last handful of years (I'm 24), I've had a recurring problem (usually only a couple of times a year) where I get these awful, rotten egg burps and every time I get them, I know that I'm going to be in terrible shape for at LEAST the rest of the day. Sometimes it lasts me up to two days. Vomiting, diarrhea, the whole nine yards. However, sometimes, I CANNOT throw up, although I know that I need to. This is the case tonight, and this happens to be the second occurrence in less than two weeks. I can't seem to figure out what the cause is, but a common factor strangely seems to be that it happens shortly after or during a visit to a specific friend's home, and it's happened in more than one home that they've lived in. They have cats, and I know at least one of the cats has a problem with worms. Could this have something to do with it, or is this just coincidence? Is there anything I can do to prevent the nausea and vomiting when I start having the burps?