Bad stomach bug: what should you know?

Gastroenteritis inflames the stomach and bowel, commonly causing nausea, vomiting, loose stools, abdominal pain, fever and reduced appetite. Viruses such as rotavirus can spread through contaminated hands, surfaces, food or drinks. Similar symptoms can have other causes, so the pattern, recent contacts, travel, food exposure and medicines are useful details. The main concern is dehydration when fluid losses exceed what you can drink.

Take frequent small sips of water or an oral rehydration drink, especially after vomiting or a loose stool. Once you can eat, try simple foods and return gradually to your usual meals. Wash hands with soap and water, clean shared bathroom surfaces, and avoid preparing food for others while unwell. Do not give children anti-diarrhoeal medicine without suitable medical advice.

Seek urgent help for confusion, fainting, severe weakness, very little urine, blood in vomit or stool, severe abdominal pain, or breathing difficulty. Get prompt advice for persistent vomiting, worsening fever, or illness in a baby, older adult, pregnant person, or someone with a significant medical condition. Assessment is also sensible when symptoms are not settling or keep returning.

How can I replace fluids safely? Could my medicines or a recent food exposure be contributing? Do I need testing, and which signs mean dehydration is becoming urgent?