Food poisoning and a stomach virus have very similar symptoms, including diarrhoea and abdominal pain. But a stomach virus (also called stomach flu or viral gastroenteritis) is caused by a virus, whereas food poisoning is usually caused by bacteria in contaminated food, such as E. coli.
Symptoms of food poisoning and a stomach virus include nausea, vomiting, diarrhoea, abdominal cramps and fever.
Length of Symptoms
Both stomach virus and food poisoning symptoms generally last one or two days, but can last up to ten days.
The most common complication of food poisoning and a stomach virus is dehydration resulting from frequent vomiting and diarrhoea. Dehydration may cause lightheadedness or dizziness.
The main difference between food poisoning and the stomach flu is that the former can cause serious illness requiring hospitalisation, or even death. This is rarely the case with a stomach virus.
Telling the Difference
In most cases, you can't tell the difference between a stomach virus and food poisoning without a lab test, unless you know the cause of your problem---for example, eating undercooked meat or being in contact with someone who has the stomach flu.
Both food poisoning and a stomach virus will usually go away on their own in a few days. Simply eat bland food, such as crackers and chicken, and drink plenty of fluids. If food poisoning symptoms are severe, your doctor may prescribe antibiotics.