how long does it take for food poisoning to show effects
1 You recognize symptoms of chemical or toxin food poisoning, such as vomiting, diarrhea, sweating, dizziness, tearing in the eyes, excessive salivation, mental confusion, and stomach pain, beginning about 30 minutes after eating contaminated food. Symptoms can last from one day up to a couple of months or longer, depending on the type of infection. 2  Vomiting, diarrhea, sweating, dizziness, tearing in the eyes, excessive salivation, mental confusion, and stomach pain may be symptoms of chemical or toxin food poisoning such as that from poisonous mushrooms.