Originally Posted by
smellme
I just want to add that the food poisoning doesn't always come directly from eating food - you can easily catch it from someone who is already sick or something that they touched, especially in the toilet.
Or from tainted water. This is where testing is useful as it should tell you what the pathogen was and whether it was water-born, bacterial or viral. Cryptosporidium for example is usually caught from water and can take a week to clear.