Stomach flu?
Influenza is a respiratory virus. Strictly speaking, there is no stomach flu.
There are, however, viruses that attack the digestive system. Norovirus and rotavirus cause the nausea, vomiting, and diarrhea that many people call “stomach flu.”If left untreated, the rapid dehydration these viruses cause can be fatal.
Bacterial food poisoning can also cause fast-onset vomiting and diarrhea.