Diarrhoea and vomiting
Diarrhoea and vomiting are very common and are usually caused by a stomach bug (gastroenteritis), such as norovirus. Most people get better at home without treatment. The main risk is dehydration, so drinking enough matters most.
- Vomiting usually stops
- Within 1 to 2 days
- Diarrhoea usually stops
- Within about 5 to 7 days
- Stay off work or school
- Until 48 hours after the last episode
Common symptoms
- Loose, watery poo
- Feeling sick and vomiting
- Stomach cramps
- A mild fever, headache and aching muscles
- Loss of appetite
What you can do yourself
- Drink small amounts of fluid often, even if you are being sick. Water is best.
- Oral rehydration sachets from the pharmacy help replace lost salts and fluids. They are especially useful for older people, young children and anyone who is frail.
- Eat when you feel able to. There is no need to starve yourself, and plain foods such as toast, rice and bananas are usually easiest.
- Avoid fruit juice and fizzy drinks, which can make diarrhoea worse.
- Take paracetamol for fever, headache or aches if it is suitable for you.
- If you are breastfeeding or bottle-feeding a baby, carry on with their usual feeds.
- Rest, and try not to prepare food for other people while you are unwell.
Medicines
Some adults find an anti-diarrhoea medicine useful for short-term relief, but these are not suitable for children, or if you have a fever or blood in your poo — ask us first. Do not give anti-sickness or anti-diarrhoea medicines to a child without advice from a pharmacist or doctor.
If you take regular medicines for blood pressure, heart conditions, diabetes or kidney problems, or anti-inflammatory painkillers, ask us or your GP whether you need to pause any while you are dehydrated. This is sometimes called following "sick day rules". Do not stop any medicine without advice.
Vomiting or severe diarrhoea can stop the contraceptive pill working. If you are sick within about 3 hours of taking your pill, or have severe diarrhoea for more than 24 hours, ask us what to do.
Stopping it spreading
- Wash your hands with soap and warm water after going to the toilet and before preparing or eating food. Alcohol hand gel does not reliably kill the germs that cause stomach bugs such as norovirus.
- Clean surfaces, toilets and taps with a bleach-based cleaner, and wash soiled clothes and bedding on a hot wash.
- Do not share towels, and stay off work or school until 48 hours after your last episode.
- Avoid swimming pools for 2 weeks after the last episode of diarrhoea.
How PRX Pharmacy can help
We can recommend oral rehydration sachets and other suitable treatments, check they are safe with your usual medicines, and tell you whether you need to see a doctor.
When to get medical help
Call 999 or go to A&E if:
- • You are vomiting blood, or your vomit looks like coffee grounds
- • You have black, tarry poo, or a lot of blood in it
- • You have severe, constant tummy pain
- • You are confused, very drowsy, floppy or difficult to wake, or you collapse
- • A baby or child is floppy, unresponsive, or has a seizure (fit)
Contact your GP practice or call 111 the same day if:
- • You have signs of dehydration: a very dry mouth, sunken eyes, dark or very little urine (or none for 8 hours or more), or feeling dizzy or faint when you stand
- • A baby under 1 year old has diarrhoea or vomiting — get advice the same day
- • A baby or child has far fewer wet nappies than usual, is very sleepy, or is refusing to drink
- • You cannot keep any fluids down for about 24 hours
- • The vomiting has lasted more than 2 days, or the diarrhoea has lasted more than a week
- • You have blood or mucus in your poo, or a high temperature
- • You are pregnant, have a weakened immune system, or have recently been abroad
- • You have recently taken antibiotics, or been in hospital
- • You are older, frail, or have a long-term condition such as diabetes, and you are struggling to keep hydrated
If you are ever worried and unsure, ask us or call 111. Trust your instincts — it is always better to ask.
This guide is general information written by the PRX Pharmacy team. It does not replace advice from a pharmacist or doctor who knows your medical history.
Last updated 24 September 2026. Clinically reviewed by Milan Patel, Pharmacist on 24 September 2026.
More health guides
Sore throat
What causes a sore throat, how to ease it at home, when a pharmacist can help, and the signs that mean you need medical advice.
Earache and ear infections
Earache and middle ear infections in children: symptoms, what helps at home, when a pharmacist can help, and when to get urgent advice.
Sinusitis (sinus infection)
Sinusitis symptoms, how to ease facial pain and congestion at home, when a pharmacist can help, and when to get urgent medical advice.
Impetigo
Impetigo: what it looks like, how it spreads, how long to stay off school or work, and how a pharmacist can treat it.
Insect bites and stings (including infected bites)
How to treat insect bites and stings, how to tell when a bite is infected, what to do about ticks, and when to get urgent help.
Shingles
Shingles symptoms, why early treatment matters, how to protect others, and when a shingles rash needs urgent medical attention.
Urinary tract infection (UTI)
UTI symptoms, what helps at home, when women aged 16 to 64 can be treated by a pharmacist, and the signs of a kidney infection.
Earwax build-up
Earwax build-up: symptoms, what to do and not do at home, when to see a doctor, and how our Herne Bay branch can remove it.
Hay fever
Hay fever symptoms, practical ways to reduce pollen exposure, the treatments a pharmacist can recommend, and when to see a doctor.
Common cold
Common cold symptoms, how long a cold lasts, what helps at home, which medicines are safe for children, and when to get medical advice.
Flu
Flu symptoms, how it differs from a cold, how to look after yourself, who is at higher risk, and how to get the flu vaccine.
Conjunctivitis (red or sticky eye)
Conjunctivitis symptoms, the difference between infective and allergic types, how to care for your eyes, and warning signs that need urgent attention.
Cold sores
Cold sore symptoms, triggers, how to speed healing and avoid spreading them, and when to seek medical advice.
Athlete's foot
Athlete's foot symptoms, how to treat it and stop it coming back, and when to see a doctor, especially if you have diabetes.
Head lice and nits
How to spot head lice, the treatment options, how to stop them coming back, and why you do not need to keep children off school.
Threadworms
Threadworm symptoms, how to treat the whole household, and the hygiene steps that stop them coming back.
Constipation
Constipation causes and symptoms, diet and lifestyle steps that help, how laxatives work, and the warning signs that need medical attention.
Heartburn and acid reflux
Heartburn and acid reflux symptoms, lifestyle changes and medicines that help, and warning signs that need medical attention, including chest pain.
High blood pressure (hypertension)
What high blood pressure is, why it matters, blood pressure readings explained, how to lower it, and how to get a free blood pressure check.
Headaches and migraine
Common types of headache, what helps, how to avoid painkiller-overuse headaches, and the warning signs that need urgent medical attention.
Cough
Causes of a cough, what helps at home, medicines for children and adults, and when a cough needs to be checked by a doctor.
Thrush
Thrush symptoms in women and men, treatments from the pharmacy, what to do to avoid it, and when to see a doctor or sexual health clinic.
Mouth ulcers
Mouth ulcers: common causes, how to ease the pain, pharmacy treatments, and when a mouth ulcer needs to be checked by a doctor or dentist.
Nappy rash
Nappy rash: how to treat and prevent it, when it might be thrush, and when to see a doctor.