Even if you have never suffered from food poisoning, you probably know what the usual symptoms are.
Food poisoning is normally an illness of the bowel (gut) and therefore the symptoms are those of gastro-enteritis (this just means inflammation of the stomach and intestines). That is:
Abdominal pain
Diarrhoea
Nausea (feeling sick)
Vomiting (being sick)
The symptoms usually, but not always, start quite soon after the contaminated food has been eaten. "The time between the consumption of the food and the first symptoms of illness" is known as the incubation or onset period. This can be as short as a couple of hours or up to several days after the contaminated food was eaten. Other non gastro-intestinal symptoms may include fever and headache.