What is happening in the body when food poisoning occurs? Are the symptoms defensive actions or purely symptomatic?
My girlfriend—her of the iron stomach—ate dinner with my parents and I the other night. First up: scallops, fried. Second: salmon steaks, fried, with various sundries. Cake and cheeseboard followed. Two glasses of wine.
Two hours later, after a walk to the beach and back, she throws up everything. In the forty-five minutes preceding she feels very queasy. After vomiting she still feels a little bad, but generally much better. We go to sleep. The next day she's mildly tired but otherwise fine.
We put it down to a bad scallop, since everyone else was unaffected. It got us talking about food poisoning. What exactly is going on? Is the vomiting a symptom forced upon the body by bacteria or, as it very much appears, something the body enacts to eject the bad stuff? Similar with diarrhea. Do the symptoms depend on the type of bacteria ingested? Are these symptoms actually defences to prevent things going any further, or are they negative consequences? Does the delay between eating and feeling sick depends on bacteria multiplying? How does the body detect a problem, if these are defensive manoeuvres?
Why is seafood so susceptible to bacteria that can sicken us? Or are most shellfish poisonings, as hinted at by the wikipedia page, a toxin poisoning?
I've read the wikipedia page
, but it doesn't really explain how the symptoms come about or what is happening in the body. I realise there are a lot of questions above. I don't mind in-depth explanations or links. Thanks.