Diarrhoea in children: rehydration that prevents death

What this article covers

Why does diarrhoea kill children when the germ itself does not?
How to make oral rehydration solution at home
What are the signs of dehydration you need to know?
Why zinc matters and when to use it
Breastfeeding and feeding: do not stop
Does the child need antibiotics?
When must the child go to hospital?
Prevention: water safety and food hygiene

Why does diarrhoea kill children when the germ itself does not?

Acute diarrhoea does not kill by the power of the virus or bacteria itself in the vast majority of cases. What kills is dehydration, the loss of water and electrolytes faster than the body can replace them. A two-year-old child can lose the equivalent of ten percent of their body weight in fluid within hours during severe diarrhoea if no replacement is given, and that loss is enough to cause circulatory shock. The sodium and potassium that are lost alongside water are not optional extras. They are essential for heart and nerve function.

The Global Burden of Disease 2023 study, published in The Lancet in 2025, confirmed that diarrhoeal disease remains one of the leading causes of death in children under five in low and middle income countries, particularly in areas with limited access to medical care. Yemen, Sudan and parts of Syria all record regular diarrhoea deaths in children, which are preventable deaths. This is not a fact about poverty alone. It is a fact about knowledge.

Here is the truth that every parent in this region deserves to know. Oral rehydration solution is one of the greatest medical discoveries of the twentieth century. Researchers have estimated it has saved tens of millions of lives since the 1970s. A child dying of dehydration in a household that can access clean water, salt and sugar is not an inevitable tragedy. It is a preventable one.

Understanding the biology helps you take it seriously. In viral gastroenteritis caused by rotavirus, the most lethal viral cause of infant diarrhoea, the gut cells that normally absorb fluid are damaged. The gut starts secreting water rather than absorbing it. ORS at its precise sodium-glucose concentration activates a separate transport mechanism in the gut cell wall that remains functional even in acute diarrhoea, allowing fluid to be absorbed by an alternative route. That is why it works even when the gut is severely inflamed.

How to make oral rehydration solution at home

Ready-made ORS sachets are available in most pharmacies and are always the first choice because the concentration is precise and guaranteed. But if sachets are not available or you are in a remote area, a home-made version using the WHO formula is a genuinely lifesaving alternative. WHO recommends ORS containing 75 to 90 millimoles of sodium per litre, which is the concentration optimal for uptake through the gut wall.

The accepted home recipe is: one litre of clean water that has been boiled and cooled, plus one level teaspoon of table salt, plus six level teaspoons of sugar. Stir until completely dissolved. This solution stays safe at room temperature for 24 hours only, after which a fresh batch must be made. In hot climates typical of the Arab summer, bacterial contamination can begin sooner, so maintaining cleanliness in preparation is essential.

The correct amount to offer: for a child under two years, 50 to 100 ml after each episode of diarrhoea. For a child aged two to ten, 100 to 200 ml after each episode. If the child is vomiting, use a teaspoon or a plastic syringe to give tiny amounts slowly rather than a cup at once. Slow and frequent is far more effective than large amounts that trigger more vomiting.

Making safe home oral rehydration solution

1Boil one litre of clean water and leave to cool completely
2Add one level teaspoon of table salt (5 grams)
3Add six level teaspoons of white sugar (30 grams)
4Stir well until both salt and sugar have fully dissolved
5Start giving immediately: around 100 ml after each diarrhoea episode
6Discard and make a fresh batch every 24 hours; keep covered in a clean container

What are the signs of dehydration you need to know?

A 2024 review in Pediatric Nephrology confirmed that careful clinical assessment remains the primary guide for judging a child's degree of dehydration and deciding whether intravenous fluids are needed. Doctors assess a cluster of signs together, not a single sign in isolation. As a parent you can learn to recognise the same patterns.

Mild to moderate dehydration looks like: a dry mouth and slightly sticky tongue, reduced or absent tears when crying, eyes that appear slightly more sunken than normal, a child who is less active than usual but still responds when you call their name, and urine that is darker yellow and less frequent than normal. At this level, home treatment with ORS given consistently is usually effective.

Severe dehydration is a different situation entirely: eyes that are visibly and deeply sunken, skin that stays in a pinched ridge instead of springing back, a child who is very difficult to rouse and unresponsive to normal stimulation, a mouth and lips that are extremely dry, no urine in more than eight hours, and in infants a fontanelle that feels sunken to the touch. These signs mean the child needs intravenous fluids in hospital and ORS alone is no longer sufficient.

Assessing dehydration level in a child

Sign	No dehydration	Moderate dehydration	Severe dehydration
Child's state	Alert and normal	Restless or lethargic	Very drowsy, hard to rouse
Eyes	Normal	Slightly sunken	Deeply sunken
Tears	Present	Reduced	Absent
Mouth	Moist	Dry	Very dry
Skin pinch	Returns immediately	Returns slowly	Stays tented

Why zinc matters and when to use it

WHO recommendations include giving zinc to every child under five years of age with acute diarrhoea, alongside ORS and not instead of it. Zinc is essential for immune function and for the regeneration of gut lining cells after infection. A systematic review published in BMC Public Health in 2011, which examined preventive zinc supplementation across developing countries, found that zinc reduced the severity and duration of diarrhoea episodes and reduced mortality from diarrhoeal disease.

The recommended dose of zinc in acute diarrhoea is 20 milligrams daily for children over six months, given for 10 to 14 days. For babies between two and six months, the dose is 10 milligrams daily. It comes as dispersible tablets or as syrup and is stocked in most pharmacies across the Arab world. Continue the zinc course after the diarrhoea stops in order to complete the process of gut repair.

Zinc is not a substitute for ORS. The order of priorities is clear: give ORS first to prevent or treat dehydration, and then add zinc to shorten the illness and reduce the chance of a severe episode. If you can only access one of the two, ORS is the absolute priority because it is what prevents death in a crisis.

Breastfeeding and feeding: do not stop

The most common mistake parents make is stopping breastfeeding or all food intake during diarrhoea, on the assumption that food makes the diarrhoea worse. This is not correct. Breastfeeding should continue throughout diarrhoea, at greater frequency than usual. Breast milk does not worsen or prolong diarrhoea. It contains protective antibodies, immune factors and growth factors that help the gut lining heal.

Formula-fed babies should continue their normal feeds alongside ORS given between feeds. There is no good evidence that diluting formula or switching to a different formula helps in most cases of acute viral diarrhoea. The gut recovers better with continued nutritional support than with restriction.

For children who are eating solid food: continue offering their normal diet in smaller, more frequent amounts. Well-cooked rice, banana, cooked apple, plain bread and chicken broth are all appropriate. Avoid very fatty foods and foods very high in sugar during the illness. The principle is continuation, not restriction. A child who is eating even a little while receiving ORS is recovering better than one who is receiving fluids alone.

Does the child need antibiotics?

The large majority of acute diarrhoea episodes in children are caused by viruses such as rotavirus and norovirus. Antibiotics kill bacteria, not viruses, so they have no effect on a viral infection and giving them adds risk without benefit. The disruption to normal gut bacteria that antibiotics cause can actually prolong recovery in viral gastroenteritis and sets up the child for a second diarrhoea episode weeks later as the gut microbiome restores itself.

Situations where antibiotics are genuinely indicated in childhood diarrhoea: visibly bloody diarrhoea suggesting a bacterial infection such as Shigella or Salmonella, diarrhoea accompanied by high persistent fever, or a laboratory-confirmed bacterial cause such as cholera. These cases need assessment by a doctor and the correct antibiotic chosen based on the organism, not a broad-spectrum antibiotic from a pharmacy without a prescription. In the Arab region where amoxicillin and ampicillin are commonly sold over the counter, this practice does not help the child and contributes to the region's serious antibiotic resistance problem.

Anti-motility drugs such as loperamide should never be given to children under twelve years of age for acute diarrhoea with fever or blood, and require caution even in older children. Slowing gut movement traps bacterial toxins inside the intestine rather than allowing them to be expelled. The three-part approach that actually works is ORS to prevent dehydration, zinc to shorten the illness, and continued feeding to support recovery. Everything else is secondary to these three and should not delay or replace them.

Herbal remedies and traditional preparations used in the region for diarrhoea, including cumin water, anise and various plant preparations, are not harmful in most cases but have no reliable evidence for effectiveness in acute infectious diarrhoea. The time spent preparing or searching for them is time that could be spent giving ORS consistently. Do not delay ORS for any alternative treatment.

When must the child go to hospital?

Some children need intravenous fluids and medical care that cannot be provided at home. Go to hospital immediately when: you see the signs of severe dehydration described above, particularly a child who cannot be roused and whose skin stays tented, or a child who is vomiting everything they drink making ORS by mouth impossible, or obvious bloody diarrhoea with fever, or a baby younger than two months who develops acute diarrhoea.

Also go to hospital: diarrhoea persisting for more than a week without improvement, more than ten episodes in a single day, or the appearance of additional worrying symptoms alongside diarrhoea such as seizures, an altered level of consciousness, or an unusual rash.

The 2025 Chinese clinical practice guideline for acute diarrhoea in children, published in World Journal of Pediatrics, echoes WHO guidance: the majority of childhood diarrhoea cases can be managed safely at home with ORS, zinc and continued feeding. Hospital is for cases where home management has failed and for severe dehydration that is beyond what oral replacement can correct.

Prevention: water safety and food hygiene

Preventing diarrhoea in children comes down to three practical levers. Breastfeeding substantially reduces the risk of both viral and bacterial diarrhoea through the first months of life. Handwashing with soap, before preparing food and after changing a nappy, interrupts the chain of transmission at the most critical point. Sterilising feeding equipment, especially in hot weather when bacterial growth is faster, is the third line.

Drinking water of uncertain safety should be boiled for a full three minutes before being used to prepare infant food or ORS solution. In displaced settings and camps where water quality is not guaranteed, water purification tablets distributed by humanitarian organisations are a reliable alternative when boiling is not possible.

Rotavirus vaccine, mentioned in our childhood vaccination article, protects against the most lethal viral cause of severe infant diarrhoea. If it is available in your current country either free on the government schedule or privately, it is a high-priority vaccine after the core schedule has been completed. The evidence for its impact on reducing severe diarrhoea hospitalisations is strong.

Track how many diarrhoea episodes your child has had, how much ORS they have taken, and whether they are producing urine using the Sihtak app. A clear record helps the doctor assess severity quickly if you need to seek help.

Frequently asked questions

Can I give fruit juice or sports drinks instead of ORS?

No. Fruit juice and fizzy drinks contain far too much sugar and far too little sodium compared to what a child losing fluid through diarrhoea needs. The wrong concentration can worsen dehydration rather than correct it. Plain water alone is also insufficient because it does not replace the electrolytes being lost. ORS is the only correct choice.

Can I give Smecta or activated charcoal to my child?

Dioctahedral smectite (Smecta) is accepted as an adjunct treatment in some guidelines and may modestly reduce the duration of diarrhoea. Activated charcoal does not have adequate evidence in acute childhood diarrhoea. Neither replaces ORS under any circumstances.

My child refuses ORS because of the taste. What do I do?

A very small amount of lemon juice can be added without meaningfully changing the concentration. Serve it slightly chilled as most children find it more acceptable cold. Use a teaspoon or plastic syringe to give tiny amounts at a time. If the child is completely refusing and you cannot get enough fluid in, that is a signal to seek medical advice.

Does mild diarrhoea with no other symptoms need a doctor?

Mild diarrhoea of fewer than four episodes per day with no fever, no blood and no signs of dehydration in a child over six months can be managed at home with ORS, zinc and continued feeding. If it continues beyond two weeks or worsens, the child needs to be seen.

Is diarrhoea during teething normal?

The popular belief that teething causes diarrhoea is not well supported by evidence. Teething infants put their hands and everything else into their mouths and are therefore exposed to more infectious agents than at other times. Diarrhoea during the teething period should be treated the same way as diarrhoea at any other time, with ORS and zinc, not left untreated on the assumption it will pass with the teeth.

Should I have stool tested in a lab when my child has diarrhoea?

Not in every case. Simple watery diarrhoea without blood and without high fever does not require laboratory testing and is managed with ORS. Stool testing is indicated for bloody diarrhoea, diarrhoea lasting more than two weeks, or suspected contact with a specific identified pathogen.

My breastfed baby has green diarrhoea. Is this dangerous?

Green colour in a breastfed infant's stool alone is not necessarily a danger sign. It can appear with a change in feeding pattern or early milk. What matters is the frequency and volume of the diarrhoea, whether blood or mucus is present, and how the baby is generally behaving. A baby who is feeding well, alert, producing wet nappies regularly and without other worrying signs does not need emergency attention for green stool alone.

Sources

This content is for health education only and is not a substitute for medical advice. If you have symptoms that worry you, see your doctor.