--- title: "Gastroenteritis: fluids, GP or 111? | HealthAnswers" description: "A tummy bug causes diarrhoea and vomiting. Fluids and 48 hours off after the last episode matter most. Blood, black stool or severe dehydration is urgent." url: https://healthanswers.co.uk/conditions/gastroenteritis/ robots: noindex --- # Gastroenteritis: fluids, GP or 111? | HealthAnswers Health A–Z A tummy bug causes diarrhoea and vomiting. Fluids and 48 hours off after the last episode matter most. Blood, black stool or severe dehydration is urgent. Written by HealthAnswers editorial team Medically reviewed by [Dr Neil Singh MBChB - nMRCGP](https://healthanswers.co.uk/our-doctors/neil-singh/) · GMC 7039648 Reviewed 13 August 2026 ## Quick answer When is a tummy bug an emergency? Gastroenteritis is a tummy bug causing diarrhoea, vomiting, or both. Most people recover at home with fluids. Get oral rehydration sachets from a pharmacy if you are struggling. Stay off work or school until 48 hours after the last episode. Call 111 if you cannot keep fluids down. Call 999 for severe dehydration or green vomit. ## Who is this page for? This page is for people in the UK who want a plain-English overview of Gastroenteritis, including when to seek help and what NHS care usually involves. It explains general information, not what is wrong with you personally. ## Who should skip this page? Skip this page if you need a diagnosis, a prescription, or emergency care. It cannot replace a GP, pharmacist, NHS 111 or 999. If you are in immediate danger, call 999; for urgent advice that is not life-threatening, call 111 in England, Scotland or Wales, or use your GP out-of-hours service in Northern Ireland. On this page 8 sections ## Key facts about gastroenteritis - Gastroenteritis is a tummy bug causing diarrhoea, vomiting, or both. - It spreads easily — stay off work or school until 48 hours after the last episode. - The main risk is dehydration; oral rehydration sachets from a pharmacy help. - Do not give anti-diarrhoea medicine to children under 12 unless a clinician says so. - Blood in diarrhoea, black stool, or vomit that looks like coffee grounds is urgent. ## Should I use this page, or skip it? Use this page if you have a sudden tummy bug and need fluids, time off, and when 111 is next. Skip it and call 999 if vomit is green, bloody or like coffee grounds, you are confused, or a child is unresponsive or struggling to breathe. This page cannot test for norovirus. [Diarrhoea](https://healthanswers.co.uk/symptoms/diarrhoea/) that lasts weeks is a different problem from a three-day bug. ## What is gastroenteritis and what does it feel like? Gastroenteritis is inflammation of the stomach and bowel, usually from a virus or bacteria. It typically starts suddenly with diarrhoea, vomiting, cramps, and sometimes a mild fever or aching limbs. Most people recover at home. The danger is [dehydration](https://healthanswers.co.uk/symptoms/dehydration/), not the germ’s name. NHS advice is that vomiting usually settles in one or two days and diarrhoea within five to seven days. ## How do I look after it at home? Drink plenty of fluids. Take small sips if you feel sick. A pharmacist can supply [oral rehydration salts](https://healthanswers.co.uk/treatments/oral-rehydration-salts/) — useful for children, older people, or heavy losses. Eat when you feel able; plain food is often easier. Avoid fruit juice and fizzy drinks. Keep breastfeeding. Use formula at its usual strength — never dilute it. Do not give anti-diarrhoea medicine to children under 12 unless a clinician says so. [Paracetamol](https://healthanswers.co.uk/treatments/paracetamol/) can ease discomfort — follow the pack. Find a GPhC-registered pharmacy on [Pick My Pharmacy](https://pickmypharmacy.co.uk/) if you need sachets or a second pair of eyes on whether 111 is next. ## How do I stop it spreading? Stay off work, school and swimming until 48 hours after the last episode of diarrhoea or vomiting. Wash hands with soap and water. Clean taps, flushes and door handles. Wash soiled laundry separately on a hot wash. Do not share towels. Do not prepare food for other people while you are infectious. Gel hand rub is less reliable against some tummy bugs than soap and water. ## When is it 111 or 999? Use 111 if you cannot keep fluids down, have bloody diarrhoea, diarrhoea lasting more than seven days, vomiting lasting more than two days, or a baby under 12 months who has stopped feeding. Call 999 for green, bloody or coffee-ground vomit, sudden severe tummy pain, confusion, blue or grey skin, or severe breathing difficulty. In England, Scotland and Wales call 111 (NHS 24 in Scotland). In Northern Ireland there is no general 111 — use GP out-of-hours on [nidirect](https://www.nidirect.gov.uk/articles/gp-out-hours-services). See [pharmacy, GP, 111 or A&E](https://healthanswers.co.uk/guides/pharmacy-gp-111-or-ae/) if you are stuck on the door. ## What should babies and older people do differently? Babies, older people, and anyone with a weakened immune system dehydrate faster and should get advice sooner. Keep breastfeeding. Use formula at its usual strength — never dilute it. Offer smaller, more frequent feeds if they are being sick. A pharmacist can supply oral rehydration sachets. Do not give anti-diarrhoea medicine to children under 12 unless a clinician says so. If a baby under 12 months has stopped feeding, that is 111 the same day, not a wait until morning unless they are already a 999 picture. ## Should I take something to stop the diarrhoea? Most people just need fluids and rest. A pharmacist can advise adults who need a few hours of control. Anti-diarrhoea medicine is not for children under 12 unless a clinician says so, and not if there is blood in the stool or a high fever. Follow the pack if you are offered a product. Eat when you feel able. Plain food is often easier. Avoid fruit juice and fizzy drinks. You can still spread a tummy bug until 48 hours after the last episode, even if you feel better. ## Who should skip this page? Skip this page if vomit is already green, bloody or like coffee grounds — that is 999, not a long read. It is not a travel-clinic stool test, not an IBS diagnosis, and not the children’s vomiting fluid plan in full. Recurrent diarrhoea belongs with a GP, not another bottle of loperamide. ## ! When to see a GP about gastroenteritis Use NHS 111 if you cannot keep fluids down, have signs of dehydration, bloody diarrhoea, diarrhoea lasting more than 7 days, or vomiting lasting more than 2 days. Seek advice sooner for babies, older or frail people, or anyone with a weakened immune system. Call **999** or go to A&E for severe dehydration, confusion, green vomit, blood or coffee-ground vomit, or a child who is unresponsive or struggling to breathe. ## Common questions about gastroenteritis How long does gastroenteritis last? NHS advice is that vomiting usually stops in one or two days and diarrhoea within five to seven days. If vomiting lasts more than two days or diarrhoea more than a week, use 111 or a GP. You can still spread it until 48 hours after the last episode, even if you feel better. How do I avoid dehydration with a tummy bug? Take small, frequent sips of water or squash even if you feel sick. A pharmacist can supply oral rehydration sachets to replace salts as well as fluid — especially useful for children, older people, or heavy diarrhoea. Do not use fruit juice or fizzy drinks, which can make diarrhoea worse. Is gastroenteritis contagious? Yes. It spreads through hands, surfaces, food and vomit droplets. Wash hands with soap and water — gel is less reliable against some tummy bugs. Stay off work, school and swimming until 48 hours after the last episode. Do not prepare food for other people while you are infectious. Should I take something to stop the diarrhoea? Most people just need fluids and rest. A pharmacist can advise on anti-diarrhoea medicine for adults who need a few hours of control. It is not for children under 12 unless a clinician says so, and not if there is blood in the stool or a high fever. Follow the pack. What should babies and children drink? Keep breastfeeding or using formula at its usual strength — never dilute it. Offer smaller, more frequent feeds if they are being sick, and small sips of water between feeds for formula-fed babies. Oral rehydration solution from a pharmacy is often more useful than plain water in young children. When is a tummy bug 999? Call 999 for vomit that is green, bloody or like coffee grounds, sudden severe tummy pain, confusion, blue or grey skin, or severe breathing difficulty. A stiff neck with dislike of bright lights is also emergency care. Blood in diarrhoea still needs 111 the same day even if you can walk. ## Sources - [NHS — Diarrhoea and vomiting](https://www.nhs.uk/conditions/diarrhoea-and-vomiting/) - [NICE — Diarrhoea and vomiting caused by gastroenteritis in under 5s (CG84)](https://www.nice.org.uk/guidance/cg84)