Patient information from BMJ

Diarrhoea in children

Last published:Aug 30, 2022

If your child has diarrhoea, he or she has loose, runny stools (poo). Most children recover completely in about a week. But there is a danger that they could lose too much fluid (become dehydrated). It’s important to prevent this and to treat it quickly if it happens.

What happens?

Diarrhoea is usually caused by a virus, most often one called rotavirus. Rotavirus is usually passed on through infected stool (poo).

A vaccine that protects against the rotavirus is available. It protects your child against rotavirus, but this does not mean that he or she will never get diarrhoea. This is because other germs can cause diarrhoea, too.

Infections can spread easily, especially among young children in nursery. Most children get diarrhoea at least once before the age of 5. But you can do a lot to stop the infection spreading.

Make sure everyone in the family washes their hands properly after using the toilet or changing a baby's nappy, and before preparing food or eating. Dispose of nappies properly. Keep your children away from anyone who has diarrhoea or vomiting.

What are the symptoms?

If your child has diarrhoea they have runny poo that comes more often than normal. They might also be sick (vomit), get belly pain, a high temperature (fever), and lose their appetite.

Most children recover completely from diarrhoea in a few days, without treatment. But there is a chance they could become dehydrated. If this happens you should take them to a doctor straight away.

Signs of dehydration include:

• being thirsty

• passing urine less often than normal (a baby's nappy might be dry)

• being restless or irritable, and

• having dry eyes or mouth.

If your child's eyes look sunken, and if they are listless or drowsy, they could already be severely dehydrated.

In a baby, the fontanelle (the soft spot on the back of a baby's head) might be sunken. Severe dehydration is life threatening. If your child has any signs of severe dehydration you should take them to the hospital’s accident and emergency department immediately.

If your child has a high fever (more than 39°C) or blood in their stools, their infection might be caused by bacteria rather than a virus. Take them to see a doctor. Sometimes these infections need to be treated with antibiotics.

What treatments work?

Diarrhoea in children is usually caused by a virus (such as rotavirus). Most children will fight off the virus without treatment. Antibiotics work only for bacteria infections (like Salmonella). The main danger with diarrhoea is that children can lose too much fluid and become dehydrated. There are treatments that can stop this happening.

Doctors don't recommend using medicines such as loperamide (brand name Imodium) to stop diarrhoea in young children.

Things you can do yourself

The most important thing when your child has diarrhoea is to replace the fluid they are losing. You should see your doctor for advice about how best to do this. This is especially important if your child is being sick or has difficulty keeping down fluids.

If you are breastfeeding your doctor will probably recommend that you continue breastfeeding. You might need to feed your baby more often or make the feeds longer. If your baby is bottle-fed he or she will probably continue with their usual formula milk.

Older children will probably be able to eat normal food if they are hungry and not being sick, but check with your doctor which foods are suitable.

Rehydration

Rehydration drinks (also called oral rehydration solutions) help the body replace fluids and salts. They don’t stop diarrhoea but they can prevent your child from getting dehydrated. Your doctor might suggest rehydration drinks for your baby or child and explain the best way to give these.

You might need to help your child drink slowly with small sips. Avoid sugary drinks such as fruit juice.

Sometimes children can't keep drinks down, won’t drink them, or need fluids very quickly. Doctors might then need to give them rehydration solutions through a drip into their arm or a tube into their stomach.

Other treatments

Some babies who have had diarrhoea for a long time might benefit from lactose-free formula milk while they recover. Ask your doctor about whether you should try a lactose-free formula for your baby.

What will happen?

Most children who have diarrhoea get better in about a week. They can usually be treated at home. But take your child to the doctor if you are at all worried, if they do not get better or are getting worse, or if they have a lot of diarrhoea or vomiting.

If your child starts to get dehydrated he or she might have to go to hospital for rehydration treatment, and to be kept a close eye on for a few days. Most children make a good recovery if they get treatment quickly.