I knew shouldn't have eaten those oysters. Your life becomes a living hell, you think you're okay at first but then it hits you. It's like swallowing a sack of hammers. First, you get the chills. Then, you get the stomach pains. Finally, you're hanging over a toilet bowl expecting a normal throw up session that will be over soon. It must be normal food poisoning, right? NO! You heave and empty your stomach into the toilet bowl, but something doesn't feel right. You heave again and as the oyster seasoned stomach milkshake flies out of your mouth your body can't help but tense up, causing you to leak liquid shit all over everything behind you. Christ, this couldn't get any worse, could it!?
Oh but it totally fucking does, you're shitting and puking at the same time, and it just doesn't end. Eventually it feels like you're excreting blades crafted from magma in the forges of hell. At this point you've either coated the floor with some body excrement or you're smart enough to have gotten a large bowl to empty your stomach into while you sit on the can emptying into that as well.
This will go on for a long time. Drink water and you'll be fine. You'll probably sleep for twenty hours, so call in sick if you have work.
The best possible way I can explain salmonella to someone who hasn't experienced it yet. Most viruses and diseases work this way though, some worse than others (Malaria, West Nile...)