My Child Can't Keep Down Fluids During Stomach Flu: What to Do and When to See a Doctor

Third time tonight. Your child has just been sick again, the floor is wiped, you offer a sip of water, and it comes straight back up. From this point the question is no longer whether your child should drink, but how.

The answer is more a technique than a particular drink: tiny amounts at steady intervals. Below that are the signs that mean you stop handling it on your own.

How do you get fluids into your child when nothing stays down?

Small amounts at short intervals work where a full glass does not. Give an oral rehydration solution from the pharmacy in regular small sips, a teaspoon at a time if your child keeps being sick, and carry on breast or bottle feeding with small amounts more often than usual.

The NHS page on dehydration describes rehydration solutions as "powders that you mix with water and then drink", and a pharmacist can suggest one. In practice:

1. Get a rehydration solution and mix it exactly. It replaces water and the salts lost through vomiting and diarrhoea. Follow the instructions on the packet.
2. A teaspoon every minute or two. One spoonful, a short pause, the next. If your child refuses the spoon, an oral syringe (no needle) often works better. A timer on your phone does the counting for you.
3. Bigger sips once it stays down. When spoonfuls are staying down, move on to small sips from a cup. There is no fixed millilitre target; if you are unsure, ask a pharmacist or call NHS 111. Ask a pharmacist early, too, if your child has a long-term condition or a weakened immune system that makes dehydration more likely.
4. Babies keep feeding. Carry on breastfeeding or using formula at its usual strength, and try to give small amounts more often than usual. If your baby has formula or solid food, give small sips of extra water too; for a baby under 6 months, boil the water first and let it cool.
5. Skip juice, fizzy drinks and caffeine. The NHS advises against fruit juice and fizzy drinks for young children, and the NHS dehydration page says to avoid caffeinated drinks when you feel sick or have been sick. Salty snacks on their own are no replacement for a rehydration solution either.

Most of the time this is enough. The next section is about the times it is not.

Which signs mean you need help now?

Some signs mean you stop spooning and get help straight away. Some of them show that your child is already seriously short of fluid. A baby under 3 months with vomiting or diarrhoea always needs a call to NHS 111 straight away, and 999 if your baby seems seriously unwell.

The first items come from the NHS page on diarrhoea and vomiting, the last from the NHS page on dehydration: cold skin, difficulty breathing or quick breaths, and unusual sleepiness count for 999 when your child also shows signs of dehydration.

One step below sits everything that needs NHS 111 now, from the NHS page on diarrhoea and vomiting and the dehydration page:

• signs of dehydration: your child seems drowsy or irritable, is unusually thirsty, has a headache or feels light-headed, has sunken eyes or a dry mouth, few or no tears when crying, fewer wet nappies, dark yellow pee or is peeing less than normal, feels dizzy when standing up and it does not go away, is breathing quickly or has a fast heart rate, or a baby's soft spot (fontanelle) sinks inwards
• you're worried about a baby under 12 months, or your child stops breast or bottle feeding
• your child keeps being sick and cannot keep fluid down
• vomiting for more than 2 days, or diarrhoea for more than 7 days, or bloody diarrhoea or bleeding from the bottom
• a child aged 5 or over still has signs of dehydration after using rehydration sachets

If a sign fits more than one list, act on the higher one: for example, fast breathing in a child who also has other signs of dehydration means 999.

When can you watch and wait?

My line for days like this: everyone gets ill, it's completely normal, and it passes.

If your child is older than 3 months, awake and responsive, peeing regularly and keeping small sips down, the situation is usually not acute. Vomiting usually stops within 1 or 2 days and diarrhoea within 5 to 7 days. Whether it really is an ordinary stomach bug is a decision for your GP; your part is noticing when things change.

Contact your GP or NHS 111 if things get worse rather than better, for example if the diarrhoea is getting more frequent. Tummy pain that does not ease, or weight loss you can see, are also reasons to call.

Not every spit-up is vomiting, by the way. Babies often bring up small amounts of milk after feeds, and that is normal as long as they are gaining weight and feeding well. Forceful vomiting that does not stop, or green or bloody vomit, are warning signs: green or bloody vomit means 999 or A&E (see the box above), and vomiting that does not stop, so your child cannot keep fluid down, means NHS 111. For babies under 3 months, call early if in doubt.

How do you keep track of fluids and nappies?

When you call for advice, the questions are nearly always the same: How much has your child kept down? When were they last sick? How often has there been diarrhoea? How many wet nappies today? After a night of spoon and timer, you usually only know roughly.

In Mona's fluid-intake log you record every amount that stayed down, plus each vomit, each stool and each wet nappy with its time. The pattern view shows whether the gaps between episodes are getting longer. So after two or three hours you can see whether things are getting better or worse, and on the phone you answer those four questions from the screen rather than from memory.

What changes when there's a temperature too?

A temperature on top of vomiting and diarrhoea adds to the fluid loss, so the threshold for asking for advice drops. Call your GP or NHS 111 sooner rather than later, even if your child otherwise seems stable. If your child cannot keep any fluid down, that alone is a reason to call 111.

If nothing is staying down, a fever syrup may come straight back up. Whether a suppository makes sense instead is something to check with a pharmacist. Never give aspirin to a child under 16, and do not give medicine to stop diarrhoea to a child under 12. For judging a temperature in general, see our article on fever in children. Either way, drinking comes before bringing the temperature down.

When can your child eat again and go back to nursery?

Once your child is keeping fluids down, offer food when they feel like eating. A long special diet is not necessary; light food such as rusks, grated apple or banana is an easy start. Babies carry on with their usual milk.

For nursery or school, the NHS rule is to stay off until there has been no vomiting or diarrhoea for at least 2 days, and to keep away from swimming pools until at least 48 hours after the symptoms stop. The same 2-day rule applies to norovirus; if in doubt, ask your GP or the nursery. After that, thorough handwashing at home matters, because some bugs stay infectious for days.