Need advice on what is the the difference between food poisoning and a stomach bug?

Onset and duration: Food poisoning refers to ingestion of a preformed bacterial toxin in food. Symptoms occur within hours. A bacterial infection results when a large bacterial load is eaten in undercooked food and causes disease (e.g. E. Coli in hamburger meat). A stomach bug usually refers to a viral infection that is contracted from another infected person or contaminated surface (e.g. Norovirus on cruise ships).