What to do after exposure to a stomach bug

There is no routine medicine that reliably prevents every stomach bug after contact. Prompt hygiene can reduce onward spread even when it cannot undo an exposure that has already happened.

Close exposure includes cleaning vomit or diarrhoea, changing a soiled nappy, sharing a bathroom or utensils, eating food handled by someone who is ill, or touching contaminated objects before touching your mouth. Gastroenteritis can have several causes, so the timing and pattern of symptoms vary.

Watch for nausea, vomiting, loose stools, abdominal cramps, fever or reduced appetite. Having contact does not confirm that you will become ill, and symptoms alone do not identify the exact germ. The immediate goal is to interrupt hand-to-mouth spread and prepare for safe hydration if sickness develops.

Wash your hands with soap and running water, particularly before eating and after using the toilet, cleaning, or handling laundry. Keep your hands away from your face until they are clean. Do not share towels, cups, cutlery or prepared food with the unwell person.

Wear disposable gloves when clearing vomit or diarrhoea, remove visible material carefully, then disinfect the area and high-touch surfaces using a product suitable for the surface and organism, following label directions. Wash contaminated clothes and bedding separately on the warmest safe cycle. If symptoms begin, take frequent small sips of fluid and avoid preparing food for other people.

Get urgent help if vomiting prevents fluid intake, urine becomes very sparse, there is blood in vomit or stool, abdominal pain is severe, or the person becomes confused, faint or difficult to wake. Urgency comes from these warning signs rather than from how likely a particular infection seems.

Seek earlier advice for babies, frail older adults, pregnant people, or anyone with kidney disease or weakened immunity. Contact a clinician if several people become ill after the same meal, exposure involved unsafe water, symptoms follow travel, or diarrhoea and fever are persistent.

Tell the clinician who was exposed, what contact occurred, when it happened, recent travel and any symptoms. Ask whether testing is needed, which rehydration fluid is appropriate, how illness may affect regular medicines, and what precautions apply before returning to food handling or caring for vulnerable people.