Eating contaminated food can cause food poisoning leading to symptoms like nausea vomiting diarrhea abdominal pain and fever within hours sometimes days or even weeks of eating contaminated food. What are the causes of food poisoning? Food poisoning is caused due to ingesting food contaminated by bacteria viruses parasites or toxins. Food can get contaminated during growing processing storage or preparation stage. Also food that isn't cooked thoroughly or cooked under unsanitary conditions can also cause food poisoning. Also expired food products usually contain bacteria and toxins. Bacteria that cause food poisoning are Salmonella E. coli Campylobacter Clostridium perfringens etc.