How long does it take to develop symptoms from food poisoning?

Varies. Staph food poisoning: preformed toxin (in creamy, mayonaise foods), onset 4-8 h after tainted food. Symptoms: nausea, vomiting, fever, diarrhea; lasts 24-48 hours. Scombroid poisoning (fresh tuna, grouper, snapper, etc): tasteless toxin, stable to cooking, histamine release; symptoms within 1/2-3h; flushing, palpitations, cramps, diarrhea; lasts 24-48h. Others: onset up to 5 d after exposure.