Infectious gastroenteritis
Acute infectious diarrhoea with or without vomiting, managed by prioritising hydration and sepsis assessment, testing selectively, avoiding harmful antibiotics in STEC, and controlling transmission and public-health risk.
Definition
Infectious gastroenteritis is acute infection and inflammation of the gastrointestinal tract causing diarrhoea with or without vomiting. It is usually self-limiting, but can cause dehydration, sepsis, acute kidney injury, HUS, invasive infection or outbreaks.
First principles
The presentation reflects the pathogen and the host response
Viruses commonly produce short-lived watery diarrhoea and prominent vomiting, while invasive bacteria can cause fever, severe cramps, inflammatory or bloody diarrhoea and extra-intestinal disease. Preformed toxins can cause abrupt vomiting and diarrhoea soon after eating. These patterns guide the differential but do not replace examination, stool testing when indicated or assessment for alternative acute-abdomen diagnoses.
This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.

