text: Depends on the type of food poisoning. There is  food intoxication that can see symptoms set in within 3 hours. This would a violent type of illness with vomitting and other symptons setting in similar to getting really drunk very fast. \n\nThere is also food infection that can see symptons set in  within 8 hours. Symptoms can be gradual similar to a flu.\n\nThe only really effective manner in which to determine whether you have had fodd poisoning is to have the doctor test a stool sample.\n\nLots of great info at: http://www.nlm.nih.gov/medlineplus/ency/article/001652.htm#Symptoms