Final answer:
The term 'stomach flu' refers to a viral infection of the stomach called gastroenteritis, which is caused by various viruses such as rotavirus and norovirus. It is not related to the influenza virus or food poisoning.
Step-by-step explanation:
The term 'stomach flu' actually refers to a viral infection of the stomach. Commonly known as gastroenteritis, it is caused by various viruses, with rotavirus being the most common cause in children and norovirus in adults. Gastroenteritis is characterized by symptoms such as nausea, vomiting, diarrhea, aches, and fever. Although it shares some symptoms with food poisoning, it is important to note that 'stomach flu' is caused by viruses, not bacteria or food contamination.