Infective gastroenteritis Norovirus Gastroenteritis is inflammation of the stomach and intestines, typically causing the sudden onset of nausea, vomiting, diarrhea, and abdominal cramps. It is most commonly due to infection (infective gastroenteritis) with viruses, bacteria, or parasites such as protozoa.
Viruses that can cause gastroenteritis include norovirus and rotaviruses. Bacterial causes for gastroenteritis include Salmonella, Campylobacter, and Escherichia coli. Parasitic causes for gastroenteritis include the protozoa that cause amebiasis (Entamoeba histolytica and giardiasis (Giardia lamblia).
The infection is usually acquired from contaminated food or water or from close contact with infected people. Less commonly, gastroenteritis may have a noninfectious cause, such as Crohn’s disease , food intolerance, or certain medications