Once the germs that cause food poisoning get into our systems, some of them release toxins. These toxins are poisons (the reason for the name "food poisoning"), and they can give a person diarrhea and vomiting. Most of the time, doctors use "food poisoning" to describe an illness that comes on quickly after eating contaminated food.
People often get diarrhea or start throwing up within a few hours after being infected. The good news is, food poisoning usually goes away quickly too. Most people recover in a couple of days with no lasting complications. When people need medical treatment for food poisoning, it's often because of dehydration.