Food poisoning symptoms vary with the source of contamination. Most types of food poisoning cause one or more of the following signs and symptoms: nausea, vomiting, watery or bloody diarrhea, abdominal pain and cramps and fever. Signs and symptoms may start within hours after eating the contaminated food, or they may begin days or even weeks later.
Sickness caused by food poisoning generally lasts from a few hours to several days. Contamination of food can happen at any point of production: growing, harvesting, processing, storing, shipping or preparing. Cross-contamination — the transfer of harmful organisms from one surface to another — is often the cause. This is especially troublesome for raw, ready-to-eat foods, such as salads or other produce.