Gastroenteritis is the inflammation of the stomach and small and large intestines. Viral gastroenteritis, then, is an infection caused by a virus that results in vomiting or diarrhea. It is often called the "stomach flu," although it is not caused by the influenza viruses.
Many different viruses can cause gastroenteritis, including rotaviruses, noroviruses, adenoviruses, type 40 or 41, sapoviruses, and astroviruses. Viral gastroenteritis is not caused by bacteria (such as Salmonella or Escherichia coli) or parasites (such as Giardia), or by medications or other medical conditions, although the symptoms may be similar. Your doctor can determine if the diarrhea is caused by a virus or by something else.
Viral gastroenteritis is contagious. The viruses that cause gastroenteritis are spread through close contact with infected persons (for example, by sharing food, water, or eating utensils).
Symptoms generally begin 1 to 2 days following infection with a virus that causes gastroenteritis, and may last for 1 to 10 days. They can include:
Persons can reduce their chance of getting infected by: