Medical questions & health advice by board certified doctors
"Why does food poisoning cause diarrhea?"
I am a 26 year old male and when I got food poisoning last week I vomited a lot. I also had diarrhea. Why does food poisoning cause these things to happen? Is it just my body flushing things out?
That is a good way of putting it. When the body senses that you have eaten something that could be dangerous, it finds ways to get rid of it as fast as possible. This whole system is controlled by the autonomic nervous system. Once it is activated and wants to remove something, the vomiting and diarrhea won't stop until your entire GI tract is empty. Sometimes the reaction is so severe, that the nausea and loose stools can continue for more than one day. Of course you should also consider the possibility that this vomiting and diarrhea represents a different illness. Viral gastroenteritis (a viral infection of the GI tract) can sometimes be mistaken for food poisoning. This is especially true if your symptoms last more than just one day. If your diarrhea was at all bloody or your vomit dark or coffee ground in nature, then you should not hesitate to get evaluated by a doctor the same day as these could be signs of a gastrointestinal bleed. Even if your symptoms have subsided, I would still suggest scheduling an appointment with your primary care physician. He or she can listen to your symptoms and decide if this really is food poisoning. If it is, then you should find out what you ate to trigger it and avoid that food in the future.