Answers to the Common Questions on Diarrhoea
Diarrhoea: straight answers to the questions people actually ask, with the figures behind them.
Passing loose or watery stools more frequently than is normal for you.
Key takeaways
- Most common cause: viral gastroenteritis, including norovirus
- Exclusion advice: stay off work or school for 48 hours after symptoms stop
- Most useful single change: Keep fluids up and use oral rehydration salts if needed.
- Commonest mistake: Antidiarrhoeal medicines if you have blood in the stool or a fever.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
What is Diarrhoea?
Passing loose or watery stools more frequently than is normal for you.
Why does it matter?
Most episodes are self-limiting infections, and the main risk in otherwise healthy adults is dehydration rather than the infection itself.
Most common cause for Diarrhoea?
Viral gastroenteritis, including norovirus.
Exclusion advice for Diarrhoea?
Stay off work or school for 48 hours after symptoms stop.
Hand hygiene for Diarrhoea?
Soap and water; alcohol gel works poorly against norovirus.
What is the single most useful thing to do?
Keep fluids up and use oral rehydration salts if needed.
What is the most common mistake?
Antidiarrhoeal medicines if you have blood in the stool or a fever.
When should I see a doctor?
Contact NHS 111 or a GP for diarrhoea lasting more than seven days, blood in the stool, severe abdominal pain, a high fever, or signs of dehydration such as dizziness on standing and passing very little urine. Seek urgent advice for babies, older adults, pregnant women and anyone immunosuppressed, who dehydrate faster. Recent foreign travel or antibiotics makes assessment more urgent.
Where to go next
- Diarrhoea: What to Do, in Order
- Myths About Diarrhoea, Checked Against the Guidance
- Diarrhoea — the reference entry
- The Evidence on Haemorrhoids, Without the Hype
- Food Intolerance: What the Evidence Actually Says
When to speak to a doctor
Contact NHS 111 or a GP for diarrhoea lasting more than seven days, blood in the stool, severe abdominal pain, a high fever, or signs of dehydration such as dizziness on standing and passing very little urine. Seek urgent advice for babies, older adults, pregnant women and anyone immunosuppressed, who dehydrate faster. Recent foreign travel or antibiotics makes assessment more urgent.
Where this comes from
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.
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