Adult stomach bug: symptoms, self-care and warning signs

Gastroenteritis is inflammation of the stomach and intestines, often triggered by an infection. It may present with watery stools, vomiting, abdominal cramps, fever, reduced appetite and tiredness. The immediate concern is fluid and salt loss, especially when vomiting prevents drinking. Symptoms can resemble food poisoning or another abdominal illness, so the pattern and severity matter.

Take frequent small sips of water or an oral rehydration solution; large drinks may worsen nausea. Resume light, familiar foods as appetite returns rather than forcing a meal. Rest, wash hands thoroughly with soap and water, avoid preparing food for others while unwell, and clean frequently touched bathroom surfaces. A pharmacist or clinician can advise whether symptom medicines suit your age, health conditions and current prescriptions.

Watch urine frequency and colour, thirst, dizziness and your ability to keep fluids down. These practical signs help show whether losses are outpacing replacement.

Arrange prompt assessment if vomiting is persistent, you cannot retain fluids, urine becomes very scant, or diarrhoea contains blood or looks black. Severe or worsening abdominal pain, marked weakness, confusion, fainting, a stiff neck, breathing difficulty or a high or persistent fever need urgent medical attention. Seek advice earlier if you are pregnant, older, immunocompromised, or living with kidney, heart or other significant disease.

Ask whether your symptoms suggest dehydration, whether testing is needed, which fluids are appropriate, and whether any regular medicines should be adjusted while you are vomiting or losing fluid. Mention recent travel, suspicious meals, sick contacts, antibiotics and the timing of every symptom.