Acute Diarrhoea in Children

Authored by , Reviewed by Dr Helen Huins | Last edited | Meets Patient’s editorial guidelines

Diarrhoea can be of sudden onset and lasting for less than two weeks (acute) or persistent (chronic). This leaflet deals with acute diarrhoea, which is common in children. In most cases, diarrhoea eases and goes within several days but sometimes takes longer. The main risk is lack of fluid in the body (dehydration). The main treatment is to give your child lots to drink; this may be by giving special rehydration drinks. Also, once any dehydration is treated with drinks, encourage your child to eat as normally as possible. See a doctor if you suspect that your child is dehydrating, or if they have any worrying symptoms such as those which are listed below.

  • Infection of the gut (gastroenteritis) is the common cause:
    • A virus is the common cause of infective diarrhoea in the UK. Sometimes it is just 'one of those germs going about'. Various viruses are easily spread from person to person by close contact, or when an infected person prepares food for others. For example, infection with a virus called rotavirus is the most common cause of diarrhoea in children in the UK. Almost every child in the UK has a rotavirus infection before they are 5 years old. Adenovirus is another common cause.
    • Food poisoning (eating food infected with germs called microbes) causes some cases of diarrhoea. Food poisoning infection is usually caused by a germ called a bacterium. Common examples are species of bacteria called Campylobacter, Salmonella and Escherichia coli (usually shortened to E. coli). Poisons (toxins) produced by bacteria can also cause food poisoning. Another group of microbes called parasites can also be a cause of food poisoning.
    • Water contaminated by bacteria or other germs is another common cause of infective diarrhoea, particularly in countries with poor sanitation.
  • Non-infectious causes of sudden-onset (acute) diarrhoea are uncommon in children. For example, inflammation of the gut (colitis), food intolerance and various rare disorders of the gut. Toddler's diarrhoea is a common cause of persistent (chronic) diarrhoea in young children.

The rest of this leaflet deals only with infectious causes of acute diarrhoea. Click the links to the various other leaflets that give more details about some of the different microbes that cause infectious diarrhoea.

Symptoms can range from a mild stomach upset for a day or two with slight diarrhoea, to severe watery diarrhoea for several days or longer. Diarrhoea means loose or watery stools (faeces), usually at least three times in 24 hours. Blood or mucus can appear in the stools with some infections.

Crampy pains in the tummy (abdomen) are common. Pains may ease each time some diarrhoea is passed. Being sick (vomiting), high temperature (fever), aching limbs and headache may also develop.

Diarrhoea often lasts for 3-5 days, sometimes longer. It often continues for a few days after any vomiting stops. Slightly loose stools may continue (persist) for a week or so further before a normal pattern returns. Sometimes the symptoms last longer.

Symptoms of lack of fluid in the body (dehydration)

Diarrhoea and vomiting may cause dehydration. Seek medical advice quickly if you suspect that your child is becoming dehydrated. Mild dehydration is common and is usually easily and quickly reversed by drinking lots of fluids. Severe dehydration can be fatal unless quickly treated because the organs of the body need a certain amount of fluid to function normally.

  • Symptoms of dehydration in children include:
    • Passing little urine.
    • A dry mouth.
    • A dry tongue and lips.
    • Fewer tears when crying.
    • Sunken eyes.
    • Weakness.
    • Being irritable or lacking in energy (lethargic).
  • Symptoms of severe dehydration in children include:
    • Drowsiness.
    • Pale or mottled skin.
    • Cold hands or feet.
    • Very few wet nappies.
    • Fast (but often shallow) breathing.

Note: severe dehydration is a medical emergency and immediate medical attention is needed.

Dehydration in children with sudden-onset (acute) diarrhoea is more likely to occur in:

  • Babies under the age of 1 year (and particularly those under 6 months old). This is because babies don't need to lose much fluid to lose a significant proportion of their total body fluid.
  • Babies under the age of 1 year who were a low birth weight and who have not caught up with their weight.
  • A breast-fed baby who has stopped breastfeeding during their illness.
  • Any baby or child who does not drink much when they have infection of the gut (gastroenteritis).
  • Any baby or child with severe diarrhoea and being sick (vomiting). (In particular, if they have passed six or more diarrhoeal stools and/or vomited three or more times in the previous 24 hours.)

For most children, diarrhoea will usually be quite mild and will get better within a few days without any treatment other than drinking plenty of fluids. You will often not need to take your child to see a doctor or seek medical advice.

However, in some circumstances, you may need to seek medical advice for your child (see below). If this is the case, the doctor may ask you questions about:

  • Recent travel abroad.
  • Whether your child has been in contact with someone with similar symptoms.
  • Whether your child has recently taken antibiotic medication.
  • Whether your child has recently been admitted to hospital.

This is to look for a possible cause of their diarrhoea. They will usually examine your child for signs of lack of fluid in the body (dehydration). They may check their temperature and heart rate. They may also examine your child's tummy (abdomen) to look for any tenderness.

Tests are not usually needed. However, in certain cases, the doctor may ask you to collect a stool (faeces) sample from your child - for example:

  • If your child is particularly unwell.
  • If your child has bloody stools.
  • If your child is admitted to hospital.
  • If food poisoning is suspected.
  • If your child has recently travelled abroad.
  • If your child's symptoms are not getting better.

The stool sample can then be examined in the laboratory to look for the cause of the infection.

As mentioned already, most children with diarrhoea have mild symptoms which get better in a few days. The important thing is to ensure that they have plenty to drink. In many cases, you do not need to seek medical advice. However, you should seek medical advice in the following situations (or if there are any other symptoms that you are concerned about):

  • If your child is under the age of 6 months.
  • If your child has an underlying medical condition (for example, heart or kidney problems, diabetes, history of premature birth).
  • If your child has a high temperature (fever).
  • If you suspect lack of fluid in the body (dehydration) is developing (see earlier).
  • If your child appears drowsy or confused.
  • If your child is being sick (vomiting) and unable to keep fluids down.
  • If there is blood in their diarrhoea or vomit.
  • If your child has severe tummy (abdominal) pain.
  • Infections caught abroad.
  • If your child has severe symptoms, or if you feel that their condition is getting worse.
  • If your child's symptoms are not settling (for example, vomiting for more than 1-2 days, or diarrhoea that does not start to settle after 3-4 days).

Diarrhoea often settles within a few days or so as a child's immune system is usually able to clear the infection. Children can usually be treated at home. Occasionally, admission to hospital is needed if symptoms are severe, or if complications develop.

Fluids to prevent lack of fluid in the body (dehydration)

You should encourage your child to take plenty of fluids. The aim is to prevent dehydration. The fluid lost if they have been sick (vomited) and/or have had diarrhoea needs to be replaced. Your child should continue with their normal diet and usual drinks. In addition, they should also be encouraged to drink extra fluids. However, avoid fruit juices or fizzy drinks, as these can make diarrhoea worse.

Babies under 6 months old are at increased risk of dehydration. You should seek medical advice if they develop sudden-onset (acute) diarrhoea. Breast-feeds or bottle-feeds should be encouraged as normal. You may find that your baby's demand for feeds increases. You may also be advised to give extra fluids (either water or rehydration drinks) in between feeds.

Rehydration drinks may be advised by a doctor for children at increased risk of dehydration (see above for who this may be). They are made from sachets available from pharmacies and on prescription. You should be given instructions about how much to give. Rehydration drinks provide a perfect balance of water, salts and sugar. The small amount of sugar and salt helps the water to be taken in (absorbed) better from the gut into the body. Home-made salt/sugar mixtures are used in developing countries if rehydration drinks are not available but they have to be made carefully, as too much salt can be dangerous to a child. Rehydration drinks are cheap and readily available in the UK and are the best treatment for your child.

If your child vomits, wait 5-10 minutes and then start giving drinks again, but more slowly (for example, a spoonful every 2-3 minutes). Use of a syringe can help in younger children who may not be able to take sips.

Note: if you suspect that your child is dehydrated, or is becoming dehydrated, you should seek medical advice urgently.

Fluids to treat dehydration

If your child is mildly dehydrated, this may be treated by giving them rehydration drinks. Read the instructions carefully for advice about how to make up the drinks and about how much to give. The amount can depend on the age and the weight of your child. If rehydration drinks are not available for whatever reason, make sure you keep giving your child water, diluted fruit juice or some other suitable liquid. If you are breastfeeding, you should continue with this during this time. It is important that your child is rehydrated before they have any solid food.

Sometimes a child may need to be admitted to hospital for treatment if they are dehydrated. Treatment in hospital usually involves giving rehydration solution via a special tube called a nasogastric tube. This tube passes through your child's nose, down their throat and directly into their stomach. An alternative treatment is with fluids given directly into a vein (intravenous fluids).

Eat as normally as possible once any dehydration has been treated

Correcting any dehydration is the first priority. However, if your child is not dehydrated (most cases), or once any dehydration has been corrected, encourage your child to have their normal diet. Do not starve a child with diarrhoea. This used to be advised but is now known to be wrong. So:

  • Breast-fed babies should continue to be breast-fed if they will take it. This will usually be in addition to extra rehydration drinks (described above).
  • Bottle-fed babies should be fed with their normal full-strength feeds if they will take it. Again, this will usually be in addition to extra rehydration drinks (described above).
  • Older children - offer them some food every now and then. However, if he or she does not want to eat, that is fine. Drinks are the most important and food can wait until their appetite returns.

Medication is not usually needed

Medicines are not normally given to stop diarrhoea to children under 12 years old. They sound attractive remedies but are unsafe to give to children, due to possible serious complications. However, you can give paracetamol or ibuprofen to ease a high temperature (fever) or headache. See the separate leaflet called Diarrhoea Medicine for further information.

If symptoms are severe, or continue (persist) for several days or more, a doctor may ask for a sample of the diarrhoea. This is sent to the laboratory to look for infecting germs (bacteria, parasites, etc). Sometimes an antibiotic or other treatments are needed, depending on the cause of the infection.

Complications from infective diarrhoea in children are uncommon in the UK. They are more likely in very young children. They are also more likely if your child has an ongoing (chronic) disease such as diabetes, or if their immune system is weakened in some way. For example, if they are taking long-term steroid medication or they are having chemotherapy treatment for cancer. Possible complications include the following:

  • Lack of fluid (dehydration) and salt (electrolyte) imbalance in the body. This is the most common complication. It occurs if the water and salts that are lost in your child's stools (faeces), or when they have been sick (vomited), are not replaced by their drinking enough fluids. If your child drinks well, then it is unlikely to occur, or is only likely to be mild and will soon recover as your child drinks.
  • Reactive complications. Rarely, other parts of the body can react to an infection that occurs in the gut. This can cause symptoms such as skin inflammation, eye inflammation (either conjunctivitis or uveitis) or joint inflammation (arthritis). Reactive complications are uncommon if a virus is the cause of the diarrhoea.
  • Spread of infection to other parts of your child's body, such as their bones, joints, or the meninges that surround their brain and spinal cord. This is rare. If it does occur, it is more likely if the diarrhoea is caused by Salmonella spp. infection.
  • Persistent diarrhoea syndromes may (rarely) develop.
  • Irritable bowel syndrome is sometimes triggered by a bout of infectious diarrhoea.
  • Lactose intolerance can sometimes occur for a period of time after infectious diarrhoea. It is known as secondary or acquired lactose intolerance. Your child's gut lining can be damaged by the episode of diarrhoea. This leads to lack of a chemical (enzyme) called lactase that is needed to help the body digest a sugar called lactose that is in milk. Lactose intolerance leads to bloating, tummy (abdominal) pain, wind and watery stools after drinking milk. The condition gets better when the infection is over and the gut lining heals.
  • Haemolytic uraemic syndrome is a rare complication. It is usually associated with diarrhoea caused by a certain type of E. coli infection - E. coli O157. It is a serious condition where there is anaemia, a low platelet count in the blood and kidney failure. If recognised and treated, most children recover well.
  • Malnutrition may follow some gut infections. This is mainly a risk for children in developing countries.

Diarrhoeal infections can very easily be passed on from person to person. Therefore, you and your child need to take measures to try to reduce this chance.

If your baby has diarrhoea, be especially careful to wash your hands after changing nappies and before preparing, serving, or eating food. Ideally, use liquid soap in warm running water but any soap is better than none. Dry your hands properly after washing. For older children, whilst they have diarrhoea, the following are recommended:

  • Regularly clean the toilets used, with disinfectant. Also, clean the flush handle, toilet seat, sink taps, bathroom surfaces and door handles at least daily with hot water and detergent. Disposable cleaning cloths should be used (or a cloth just for toilet use).
  • If a potty has to be used, wear gloves when you handle it, dispose of the contents into a toilet, then wash the potty with hot water and detergent and leave it to dry.
  • Make sure your child washes their hands after going to the toilet. Ideally, they should use liquid soap in warm running water but any soap is better than none. Dry properly after washing.
  • If clothing or bedding is soiled, first remove any stools (faeces) into the toilet. Then wash in a separate wash at as high a temperature as possible.
  • Don't let your child share towels and flannels.
  • Don't let them help to prepare food for others.
  • They should stay off school, nursery, etc, until at least 48 hours after the last episode of diarrhoea or being sick (vomiting). Sometimes this time may be longer with certain infections. Check with your doctor if you are not sure.
  • If the cause of diarrhoea is known to be (or suspected to be) a germ called Cryptosporidium spp., your child should not swim in swimming pools for two weeks after the last episode of diarrhoea.

The advice given in the previous section is mainly aimed at preventing the spread of infection to other people. But, even when we are not in contact with someone with infectious diarrhoea, proper storage, preparation and cooking of food and good hygiene help to prevent us catching an infection. In particular, always wash your hands and teach children to wash theirs:

  • After going to the toilet (and after changing nappies).
  • Before touching food. And also, between handling raw meat and food ready to be eaten. (There may be some germs (bacteria) on raw meat.)
  • After gardening.
  • After playing with pets (healthy animals can carry certain harmful bacteria).

The simple measure of washing hands regularly and properly is known to make a big difference to the chance of developing gut infections and diarrhoea.

You should also take extra measures when in countries of poor sanitation. For example, avoid water and other drinks that may not be safe and avoid food washed in unsafe water.

Breastfeeding is also protective. Breast-fed babies are much less likely to develop infectious diarrhoea compared to bottle-fed babies.


As mentioned earlier, rotavirus is the most common cause of infective diarrhoea in children. There is an effective vaccine against rotavirus. In the UK it was decided to routinely vaccinate babies against rotavirus. From September 2013 drops (by mouth) have been available to prevent rotavirus, along with their other routine vaccinations. These drops are given at 2 and 3 months old.

Further reading and references