What is diarrhoea?

Diarrhoea is when your bowel movements are more frequent or looser than normal. If your child passes 3 or more loose or liquid stools (poos) in a day, it's diarrhoea.

If their stools are soft, formed and solid, then it's not diarrhoea. Breastfed babies may pass soft, loose stools in a mustard yellow colour, but this is not diarrhoea either. See this article for what's normal for baby poo.

Diarrhoea in children is often due to 'gastro' — viral gastroenteritis — which is infectious and easily spread from person to person.

What symptoms are related to diarrhoea in children?

Children with diarrhoea may also have other symptoms, including:

• abdominal pain (tummy pain)
• vomiting
• fever or high temperature
• loss of appetite

Depending on the cause of the diarrhoea, the symptoms may vary.

Dehydration in babies, infants and children

Children with diarrhoea can easily become dehydrated. Dehydration can be serious, even fatal. Babies or small children are particularly vulnerable to becoming dehydrated when they have diarrhoea. They can become unwell very quickly.

It's important to recognise if your child is dehydrated. The signs include:

• dry mouth, tongue and lips
• sunken eyes
• being listless or irritable
• shedding fewer tears when crying
• fewer wet nappies or wees than usual

Severe dehydration is a medical emergency and can be fatal — get medical help for your child immediately.

Symptoms of severe dehydration include:

• not drinking much or refusing to drink
• feeling lethargic
• making no urine (wee) or only a very reduced amount of urine
• very sunken eyes
• very sunken fontanelle in a baby
• cold, pale or blotchy skin
• fast breathing

Your child may need to go to hospital for rehydration and treatment.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

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What causes diarrhoea in children?

Diarrhoea happens when not enough water is removed from your child's stool at the end of digestion. Or their body secretes too much fluid into the stool, making it loose.

There are many different causes of diarrhoea in children. It can be caused by a short-term infection or be a symptom of an ongoing problem or chronic condition.

Viral gastroenteritis

Gastroenteritis is an infection of the bowel. Viruses are the most common cause of gastroenteritis in children. Rotavirus, norovirus, adenovirus and astrovirus can all cause gastroenteritis. These viruses are very infectious and are passed easily from person to person. Outbreaks happen more often in autumn and winter.

Viral gastroenteritis normally starts with vomiting, which can last 1 or 2 days. There may be a low-grade fever. The diarrhoea, which is often watery, may go on for up to a week to 10 days.

Bacterial gastroenteritis

Bacterial gastroenteritis is an infection of the bowel caused by bacteria such as salmonella, E. coli, shigella and campylobacter. These bacteria are sometimes linked to food poisoning.

Bacterial gastroenteritis may cause blood or mucus in the stool and high fever. It usually comes on suddenly.

Parasites

Parasites such as giardia and cryptosporidiosis may also cause gastroenteritis. These parasites live in rivers, lagoons and streams throughout Australia. They may also infect swimming pools, water parks and tank water.

Giardia is common in Indigenous communities. It can cause ongoing or severe diarrhoea, stomach cramps, tiredness and weight loss.

Symptoms of cryptosporidiosis include watery diarrhoea and stomach cramps, along with nausea, vomiting and loss of appetite.

Antibiotics

A course of antibiotics can sometimes wipe out 'good' bacteria as well as 'bad'. This leaves an imbalance of bacteria in the bowel, which can cause diarrhoea. This is called antibiotic-associated diarrhoea. See your doctor if you think antibiotics have caused your child's diarrhoea.

Clostridium difficile (also known as C. diff) is an example of a bacteria that can overgrow after a course of antibiotics. It can cause serious symptoms such as cramping, abdominal pain, fever and blood in the stool.

You should take your child straight to the doctor or hospital emergency room if they have blood in their poo.

Chronic (ongoing) constipation

Constipation is when your child has hard poos and does not regularly go to the toilet.

Children with long-term constipation can sometimes have an overflow of watery stool and soil their underpants.

Lactose intolerance

Lactose intolerance is when your body can't digest lactose (a sugar found in milk and dairy products). It is not common in babies and children. When lactose intolerance does occur, it causes diarrhoea and tummy pain.

Temporary lactose intolerance sometimes occurs after gastroenteritis. If you think your baby or child is lactose intolerant, see your doctor. Don't try to change their diet yourself.

Inflammatory bowel disease (IBD)

Crohn's disease and ulcerative colitis are 2 conditions collectively known as inflammatory bowel disease. The symptoms, including diarrhoea, can flare up and then die down (remit).

If your child has IBD they may lose weight for no obvious reason.

Coeliac disease

Coeliac disease is an autoimmune condition where you are abnormally sensitive to gluten. It can cause diarrhoea, bloating, abdominal pain and weight loss or slow growth in children.

Malabsorption

Malabsorption syndrome refers to several disorders that affect your ability to absorb nutrients from food. If your child has malabsorption, they may have ongoing diarrhoea and difficulty gaining weight.

How is the cause of diarrhoea diagnosed?

Your doctor will ask about your child's symptoms and if they have recently been on antibiotics or had contact with anyone with similar symptoms. They will also examine your child.

Tests may not be needed if a short-term infectious cause for the diarrhoea is suspected. Sometimes, a stool test or blood test may be recommended.

If your child has ongoing diarrhoea and is not getting better, your doctor may refer you to a gastroenterologist or other specialist to work out the cause.

When should my child see a doctor?

Bring your baby to see a doctor if they have diarrhoea and:

• are younger than 6 months or weigh less than 8kg
• they were born preterm, or have ongoing health problems

When should I seek urgent care for my child?

See your doctor straight away or go to your local hospital emergency room if your child has diarrhoea and:

• has blood or mucus in their stool (poo)
• has severe abdominal pain or constant tummy pain
• has green vomit or keeps vomiting
• has a high fever (above 38.5 C)
• shows signs of dehydration (see above)
• is tired or drowsy
• is not getting any better or cannot take in fluids

How is diarrhoea in babies and children treated?

The treatment for diarrhoea in babies and children depends on the severity (how bad it is) and the underlying cause.

How do I care for a child with diarrhoea at home?

If your child is at least 6 months old and has diarrhoea due to viral gastroenteritis they can be treated at home by following the advice below. Babies younger than 6 months should always be taken to the doctor.

• Breastfed babies older than 6 months should continue to be breastfed but they should be fed more often. If they vomit, offer them a drink after each time. You can also offer them oral rehydration solution or water for the first 12 hours.
• Bottle-fed babies should have their formula replaced with oral rehydration solution or water for the first 12 hours, then they can have normal formula in small amounts, more often than normal feeding. If they vomit, they should be offered a drink after every time.
• Oral rehydration solutions are strongly recommended for infants and toddlers with diarrhoea and any child with frequent diarrhoea or vomiting.
• Give older children small amounts of fluids to drink often — say every 15 minutes. Oral rehydration solutions are best, but if they won't drink those, very diluted cordial (one part cordial to 20 parts of water) or diluted soft drink or juice (one part juice to one part water) may be used with caution. Do not use diet or low-kilojoule versions.
• Alternatively, oral rehydration solution can be chilled or made into ice blocks for a child to suck.
• Don't give your child undiluted drinks that are high in sugar, such as sports drinks, lemonade or cordial — they can make diarrhoea or dehydration worse.
• Children with gastroenteritis may refuse solid food, but it's good for them to return to their normal diet as soon as possible so long as they are not dehydrated or vomiting.
• Make sure your baby or child rests.

Your child may need to go to hospital for fluids if they are very dehydrated. In hospital they can get fluids intravenously via a drip.

Medicines for diarrhoea

You can buy oral hydration solutions over the counter from your pharmacist or the supermarket. Oral rehydration solutions are better than plain water because they contain the right concentration of salts to replace both fluids and electrolytes (salts and minerals needed for body functions).

Anti-diarrhoeal medicines should not be used to treat diarrhoea in children.

Other treatment options

The table shows some other ways a doctor might treat a baby or child with diarrhoea.

Likely cause of diarrhoea	How it is treated
Gastroenteritis	Treatment will focus on keeping your child hydrated and replacing any lost minerals and salts. Gastroenteritis will usually clear up without specific treatment.
Antibiotic-associated diarrhoea	Your doctor may advise you to stop or change the antibiotic if it causes diarrhoea.
Coeliac disease or lactose intolerance	These conditions can be treated with dietary adjustments. Ask your doctor or a dietician.
Constipation	Ongoing constipation that causes overflow diarrhoea needs to be managed by a doctor or a paediatrician.
Cryptosporidiosis	There is usually no specific treatment for this condition, and it generally clears up by itself.
Giardia	This can be treated with specific antibiotics.
Inflammatory bowel disease (IBD)	Your child will need to see a specialist and may need medicines and specialised formula.
Malabsorption	Treatment will depend on the underlying cause and may involve replacing missing nutrients.

Can diarrhoea in children be prevented?

Gastroenteritis is highly infectious and easily spread between people, especially between children.

You can help minimise the spread of gastroenteritis by:

• Washing your hands regularly, especially after nappy changes and before feeding.
• Washing your hands before food preparation and after going to the toilet.
• Wearing gloves when cleaning up diarrhoea or vomit and sealing it in a plastic bag before putting in the bin.
• Following good food safety practices.
• Keeping your child away from nursery, day care or school until they have not had a loose bowel motion for 24 hours.
• Making sure your children are vaccinated against rotavirus.

What complications can occur in children with diarrhoea?

Dehydration is the most serious complication of diarrhoea in young children and babies.

Lactose intolerance can happen after gastroenteritis. It normally gets better after a couple of weeks.

Resources and support

If you need advice on caring for your child with diarrhoea, call healthdirect on 1800 022 222 (known as NURSE-ON-CALL in Victoria) to speak with a registered nurse, 24 hours, 7 days a week.

You can also call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call. Available 7am to midnight (AET), 7 days a week.

For more information and support, try these resources:

• The Royal Children's Hospital Melbourne
• The Sydney Children's Hospitals Network

Information in different languages:

• The Sydney Children's Hospitals Network has a translated factsheet on gastroenteritis.
• Health Translations has translated information on many health topics including foodborne diseases.