system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How and when does the body recognize food poisoning?

For example, you can eat something off, and the stomach says O HELL NO and you are vomiting within 20 minutes. However you can also eat something bad, and the body doesn't seem to notice until a few hours later it reaches the intestines (or maybe colon?). Then at that point, the body says, "Please use the nearest exit. The nearest exit may be behind you." So your abdomen is in pain (for hours) as you have to empty your bowels until the 'poisoned' waste can be evacuated.

Does it have to do with the stomach detecting some things and the intestinal tract another? Different bacteria present at different times? 

ETA: Not to be too graphic, but the times I've had food poisoning diarrhea, the smell is exceptionally foul. Is that a function of the bacteria itself or the fact that I'm passing 'unprocessed' waste? If that makes sense.
gpt
so there's a difference between **food poisoning** and **foodborne illness.**

in food poisoning, the bacteria grew in the food, and released toxins into the food. So what makes you sick is the bacterial toxins  that are already in the food when you eat it. In many cases, cooking won't eliminate the toxins, but it will kill the bacteria.That's going to make you sick very quickly.

Foodborne illness is when there are bacteria or viruses in the food, which cause an infection in your digestive system when you eat it. That takes longer, because the bacteria have to mutiply inside you before the symptoms start. Salmonella and E. Coli are examples of this. The symptoms sometimes don't show up until several days later, and they tend to last longer.