I've had it once, and I think it hit me like at least 12-16 hours later. In the commercial area of the Orlando Airport, there are these "roach coaches", basically delivery-looking trucks gutted and turned into mobile food service vehicles. One of them served Chinese food. One evening I went to this place, just as they were closing down, and ordered 2 Egg Rolls. I think the guys had to re-start the fryers as they were about to close up shop for the night (around 10PM or so). Well, they tasted just fine at that time, but the next day around 5-6PM or so it hit me hard. I hadn't thrown up in literally 15 years and I puked my guts out that evening. I don't think I had diarrhea but I felt so incredibly weak. Couldn't even drive myself to the hospital.
Went to the ER, and waited for like 2-3 hours and still hadn't been sent to a room yet. Talked to another patient in the ER that was there for chest pain and she had been there like 5 hours. I decided what I really needed was sleep, so I got driven home. Got some rest and was ok the next day. Man, that royally blew.