Nausea, vomiting, diarrhea and abdominal pain are the most common group of symptoms in people with salmonella, shigella, campylobacter or E. Coli, bacteria that enter through the intestines. Bacteria infect the lining of the intestines, producing toxins that cause the symptoms.
Your body pulls fluid into the intestine to wash the bacteria out more quickly, causing diarrhea, or tries to expel the bacteria through vomiting. Although these symptoms cause discomfort, they’re your body’s way of ridding itself of the toxins, so don’t try to stop them with anti-emetics or anti-diarrheal medications unless you have symptoms so severe that you become dehydrated.