Few childhood illnesses disrupt family life quite as quickly as a stomach bug. A child can seem completely well in the morning and suddenly develop vomiting, diarrhoea, stomach cramps, or fever later in the day.
Most cases of gastroenteritis in children are caused by infections and improve with time. The biggest concern, particularly for babies and young children, is often not the vomiting or diarrhoea itself but the fluid and salts being lost from the body.
Children can become dehydrated more quickly than adults.
Knowing how to offer fluids, what foods to give during recovery, and which warning signs require medical care can help parents manage stomach bugs more confidently.
What Is a Stomach Bug?
The term “stomach bug” commonly refers to gastroenteritis, an infection or inflammation affecting the stomach and intestines.
Viruses are a common cause in children, although bacteria and other causes are possible.
Symptoms can include:
▪ Vomiting
▪ Watery or loose diarrhoea
▪ Stomach cramps
▪ Nausea
▪ Fever
▪ Reduced appetite
▪ Tiredness
Some children mainly experience vomiting, while others have predominantly diarrhoea.
Symptoms and duration vary according to the cause and individual child.
How Do Stomach Bugs Spread?
Infectious gastroenteritis can spread very easily.
Germs may pass through contaminated hands, surfaces, food, water, or contact with vomit or faeces.
This is why stomach bugs can spread rapidly through families, nurseries, and schools.
Good hand hygiene is particularly important.
Wash hands thoroughly with soap and water after changing nappies, helping children use the toilet, cleaning up vomit, and before preparing or eating food.
Clean contaminated surfaces appropriately and avoid sharing towels where possible.
The Main Concern: Dehydration
Vomiting and diarrhoea cause the body to lose water and important salts.
Children can become dehydrated if they lose more fluid than they are able to replace.
Babies and younger children can be particularly vulnerable because their bodies are smaller.
The risk increases when vomiting and diarrhoea occur together or when a child refuses to drink.
This makes hydration the main priority during most uncomplicated stomach bugs.
Signs of Dehydration in Children
Parents should monitor how much their child is drinking and urinating.
Possible signs of dehydration include:
▪ Urinating less often or fewer wet nappies
▪ Darker urine
▪ Dry mouth or lips
▪ Few or no tears when crying
▪ Sunken-looking eyes
▪ Unusual tiredness or irritability
▪ Increasing thirst
More serious dehydration can cause significant drowsiness, weakness, confusion, very little urine, or other worrying changes.
A baby may also develop a sunken soft spot on the top of the head.
Seek prompt medical advice if you suspect significant dehydration.
Offer Small Amounts of Fluid Frequently
A child who has just vomited may struggle to drink a large glass of water.
Small, frequent amounts can sometimes be easier to tolerate.
Offer appropriate fluids regularly rather than expecting the child to drink a large quantity at once.
If vomiting continues, an oral rehydration solution may be recommended.
These solutions contain water, sugars, and salts in carefully designed proportions to replace what is being lost.
A pharmacist or healthcare professional can advise whether an oral rehydration solution is appropriate for your child and how it should be given.
Continue Breastfeeding
Breastfed babies can generally continue breastfeeding during gastroenteritis.
Offering more frequent feeds may help maintain hydration.
Formula-fed babies should usually continue receiving their normal formula unless a healthcare professional advises otherwise.
Do not dilute infant formula beyond the manufacturer’s instructions in an attempt to provide additional water.
Babies with repeated vomiting, diarrhoea, reduced feeding, fewer wet nappies, or signs of dehydration should receive appropriate medical advice promptly.
Should Children Drink Only Water?
Water can contribute to hydration, but when a child is losing substantial fluid and salts through repeated vomiting or diarrhoea, water alone may not always provide what is needed.
Oral rehydration solutions are specifically formulated for this purpose.
Avoid making homemade rehydration mixtures unless instructed by an appropriate healthcare professional because incorrect proportions can be unsafe.
Sports drinks and sugary soft drinks are also not equivalent to oral rehydration solutions and may contain inappropriate amounts of sugar or electrolytes for a sick child.
What Should Children Eat?
Parents often wonder whether children with diarrhoea should stop eating.
Once a child can tolerate fluids and feels ready to eat, normal age-appropriate foods can generally be gradually reintroduced.
Offer simple familiar foods according to appetite.
Possible options might include rice, potatoes, bread, pasta, yoghurt where appropriate, fruit, vegetables, soups, eggs, or other normal family foods.
There is usually no need to force children to eat when they have little appetite.
Hydration is the priority during the acute stage.
Do Children Need the BRAT Diet?
Parents may have heard of the BRAT diet — bananas, rice, applesauce, and toast.
While these foods can certainly be eaten if a child enjoys them, an unnecessarily restrictive diet may not provide enough nutritional variety during recovery.
Children can usually return gradually to their normal balanced diet as they begin feeling better.
Follow individual medical advice if your child has particular nutritional needs or if a healthcare professional recommends temporary dietary changes.
Avoid Very Sugary Drinks
It can be tempting to give children whatever they are willing to drink.
However, very sugary drinks can sometimes make diarrhoea worse because large amounts of sugar can draw additional water into the intestines.
Water, breast milk, normal feeds, and an appropriate oral rehydration solution when recommended are generally more useful choices.
If your child refuses all fluids, seek medical advice rather than relying indefinitely on sugary drinks.
Should You Give Medicine for Diarrhoea?
Do not give children anti-diarrhoeal medicines designed for adults unless specifically instructed by a healthcare professional.
Some products are not appropriate for children and may cause harm.
Antibiotics are also not routinely needed because many stomach bugs are viral.
A healthcare professional will decide whether testing or specific treatment is necessary when symptoms suggest a bacterial or another cause.
Medication for fever or discomfort should also be age-appropriate and given according to professional or product guidance.
Help Your Child Rest
Stomach bugs can leave children exhausted.
Allow plenty of rest and quiet activity.
A child may sleep more than usual while recovering, but they should still be appropriately responsive when awake.
There is an important difference between a tired child who wants to sleep and a child who is unusually difficult to wake or barely responding.
Significant drowsiness or altered responsiveness requires urgent medical attention.
Stomach Pain and Cramping
Mild stomach cramps can accompany gastroenteritis.
However, severe or persistent abdominal pain should not automatically be blamed on a stomach bug.
Seek medical assessment if pain is intense, localised to one area, becomes progressively worse, or occurs with a swollen or very tender abdomen.
Appendicitis and other conditions can initially produce vomiting, stomach pain, or reduced appetite and may be mistaken for gastroenteritis.
If something about the pain seems unusual or severe, have your child assessed.
Blood in Vomit or Stool
Blood requires additional attention.
Seek prompt medical advice if you notice blood in your child’s stool or vomit.
Green vomit, particularly in a child who appears unwell or has significant abdominal pain, also requires urgent medical assessment.
Parents should not assume every episode of vomiting and diarrhoea is a routine viral infection when unusual symptoms are present.
When Should You Seek Medical Help?
Contact an appropriate healthcare professional if your child:
▪ Cannot keep fluids down
▪ Shows signs of dehydration
▪ Has blood in the stool or vomit
▪ Has severe or worsening abdominal pain
▪ Has persistent or unusually severe symptoms
▪ Is becoming increasingly sleepy or unwell
▪ Has a significant fever or other concerning symptoms
Young babies deserve particularly cautious assessment.
Children with underlying medical conditions or weakened immune systems may also need professional advice sooner.
When Is It an Emergency?
Seek urgent medical care if your child becomes very difficult to wake, confused, severely weak, has serious breathing difficulties, shows signs of severe dehydration, or appears critically unwell.
Very little or no urination combined with significant illness is also concerning.
Severe abdominal pain, a rigid or swollen abdomen, green vomit, or other dramatic changes should not be managed simply by waiting for the stomach bug to pass.
Parents should seek emergency help whenever a child’s condition is deteriorating rapidly.
Returning to School or Nursery
Children with infectious vomiting and diarrhoea can easily spread illness to others.
Schools and nurseries generally have rules about how long children should remain at home after symptoms stop.
Follow your childcare provider’s policy and local public-health guidance.
Do not send a child back simply because they are bored at home.
They should also be well enough to eat, drink, participate in normal activities, and manage the school day comfortably.
Recovery Can Take Time
Vomiting may stop before appetite fully returns.
Children can remain tired or eat less than usual for a short period after a stomach bug.
Continue offering fluids and gradually return to normal meals according to appetite.
Monitor your child for signs that symptoms are returning or worsening.
If diarrhoea continues for longer than expected, your child is losing weight, remains unusually tired, or does not seem to be recovering, seek medical advice.
Frequently Asked Questions
What is the biggest concern when a child has vomiting and diarrhoea?
Dehydration is one of the main concerns, particularly in babies and young children. Monitor drinking, urination, alertness, and other possible signs of fluid loss.
What should I give my child to drink after vomiting?
Small, frequent amounts of appropriate fluid may be easier to tolerate than a large drink. An oral rehydration solution may be recommended when significant fluid and salts are being lost.
Should I stop giving my child food during diarrhoea?
Children can generally gradually return to normal age-appropriate foods once they can tolerate fluids and feel ready to eat. There is usually no need to force food when appetite is temporarily reduced.
How can I tell if my child is dehydrated?
Reduced urination, fewer wet nappies, darker urine, dry mouth, few tears, sunken eyes, unusual tiredness, or significant thirst can be warning signs. Seek medical advice if you are concerned.
When should vomiting or diarrhoea be treated as an emergency?
Seek urgent medical attention if your child is severely dehydrated, extremely drowsy or difficult to wake, has severe abdominal pain, green vomit, significant blood in vomit or stool, or appears to be deteriorating rapidly.
