Diarrhoea in children: why ORS and zinc are still the best treatment

Most diarrhoea in young children is caused by a virus and gets better on its own. What keeps a child safe while it runs its course is fluid with the right amount of salt and sugar (ORS), a short course of zinc, and normal food. Antibiotics and medicines to stop the motions are rarely needed, and some are dangerous in small children.

What is the best treatment for diarrhoea in children?

The best treatment is low osmolarity ORS, zinc tablets, and continued feeding. This is what the WHO and the Indian Academy of Pediatrics (IAP) recommend for every child with watery diarrhoea.^1,2

ORS replaces the water and salts lost in the stool. Zinc shortens the illness a little. Food keeps your child from losing weight. Every monsoon Dr Dutta sees toddlers who arrive with a bag of syrups and antibiotics but no ORS. The packet that costs a few rupees is the part that works.

Why does ORS work better than plain water?

ORS works because the gut can still absorb salt and sugar together during diarrhoea, and water follows them back into the body. Plain water has no salt, so it cannot replace what is lost.

In the WHO manual, oral rehydration safely treats dehydration in more than 90 percent of cases that are not severe.¹ The formula was later changed to low osmolarity ORS (a little less salt and sugar, closer to body fluids). Compared with the old formula, children on it needed fewer unplanned drips, passed less stool and vomited less.³ Look for "WHO formula" or "low osmolarity" on the sachet.

How do I make ORS at home from a sachet?

Dissolve one sachet in exactly the amount of clean water printed on the pack, usually 1 litre. Do not guess the volume.

• Wash your hands first.
• Use boiled and cooled, or filtered, drinking water.
• Measure with a 1 litre bottle or jug.
• Stir well. Do not add sugar, salt, glucose or juice.
• Keep it covered and make a fresh batch every day.

The common mistake is mixing a whole sachet in one glass. Strong ORS can make diarrhoea worse and push blood salt too high. If your child drinks only a little, still make the full litre and keep it in the fridge.

How much ORS should I give my child?

As a guide, give 50 to 100 ml after each loose stool to a child under 2 years, and 100 to 200 ml to a child aged 2 to 10 years.¹ Older children can drink as much as they want.

Give it slowly. For a baby, a teaspoon every 1 to 2 minutes works well. A toddler can take small sips from a cup. Children who drink too fast are more likely to vomit, so small spoonfuls work better than a big cup.¹

If a child is already a little dehydrated, the doctor works out a larger amount, about 75 ml for each kilogram of weight, given over 4 hours under watch.¹

What if my child vomits the ORS?

Wait 5 to 10 minutes, then start again more slowly, about one spoonful every 2 to 3 minutes.¹ Vomiting often settles once the child is less dry.

Vomiting from a stomach virus usually lasts 1 to 2 days and stops within 3 days in most children.⁴ If nothing stays down, your doctor may give one dose of ondansetron (an anti-vomiting medicine). In trials, oral ondansetron helped more children stop vomiting and fewer needed a drip.⁵ Older anti-vomiting syrups that cause drowsiness should not be given to children with diarrhoea.¹

Can I make ORS at home without a packet?

A home sugar and salt mix can work, but the WHO does not generally advise it because the recipe is easy to get wrong.¹ Too much salt is dangerous for a small child.

If you have no sachet at night, give fluids your child already takes that contain a little salt: salted rice water (bhaater phan), dal water, thin salted buttermilk, or soup with salt.¹ Buy proper ORS the next morning. Every pharmacy and government health centre has it.

Which drinks should I avoid when my child has loose motions?

Avoid sweet drinks. Cola, packaged fruit juice and sweetened tea can pull more water into the gut and make diarrhoea worse.¹

Coffee and herbal purging teas should also be avoided.¹ Glucose powder mixed in water is not ORS. Coconut water and plain water are fine as extra drinks, but they should not replace ORS in a child who is losing a lot of fluid.

Why does my child need zinc for diarrhoea?

Zinc shortens the illness a little and helps prevent the next bout. In Indian children, many of whom have low zinc stores, it is part of standard treatment.²

A Cochrane review found that in children over 6 months, zinc cut diarrhoea by about half a day on average, and fewer children were still ill on day seven.⁶ The benefit was larger in undernourished children.⁶ The WHO adds that a full course lowers the chance of new episodes over the next 2 to 3 months.¹ Zinc can make some children vomit.⁶ Dr Dutta suggests giving it after a feed.

How much zinc and for how long?

The IAP recommends 20 mg of zinc a day for children over 6 months, and 10 mg a day for babies aged 2 to 6 months, for 14 days.² Start as soon as the diarrhoea begins.²

The dispersible tablet can be dissolved in a spoon of breast milk or water.² Do not give it together with an iron syrup, because iron reduces zinc absorption.²

Most parents stop zinc when the motions settle on day three or four. Please finish all 14 days. To be honest about the evidence: for babies under 6 months, the trial evidence for zinc is weak, and the Cochrane review found no clear benefit in that age group.⁶ Your doctor will decide for a young baby.

What should I feed my child with diarrhoea?

Keep feeding your child's normal food. Food should never be stopped or watered down during diarrhoea.¹

Children whose food is cut back lose weight and stay ill longer.¹ Good choices in an Indian kitchen:

• Khichdi, rice with dal, curd rice.
• Mashed banana, which also gives potassium.¹
• Chapati, idli, egg, fish or chicken if your child usually eats them.
• Small meals every 3 to 4 hours.¹

After the illness, give one extra meal a day for at least 2 weeks to catch up.¹

Should I stop breastfeeding or milk during diarrhoea?

No. Breastfeed as often as your baby wants, even more than usual.^1,4 ORS goes in between feeds, not instead of them.

Formula-fed babies should keep getting their usual milk at normal strength.¹ Special "diarrhoea formulas" are costly and not needed for most babies. True milk intolerance is uncommon.¹ If stools clearly worsen every time milk is given, talk to your doctor before you change anything.

Does my child need an antibiotic for loose motions?

Usually not. Most watery diarrhoea is caused by viruses, and antibiotics do nothing to them. The WHO advises against routine antibiotics for diarrhoea in children.¹

Antibiotics help in a few situations only:¹

• Blood in the stool (dysentery).
• Suspected cholera with severe dehydration.
• Proven Giardia (a gut parasite) with diarrhoea lasting 14 days or more.
• Another infection at the same time, such as pneumonia or a urine infection.

Unneeded antibiotics cost money, can cause side effects, and help resistant bacteria spread.¹ Medicines such as metronidazole or ofloxacin are often sold for ordinary "loose motions". Most children do not need them.

Are medicines to stop diarrhoea safe for children?

No. Medicines that slow the gut, such as loperamide, should not be given to young children.¹

They make the stool count look better while fluid stays trapped inside. In a review of trials, serious side effects, including a paralysed bowel, drowsiness and death, occurred only in children under 3 years.⁷ The WHO says no anti-motility drug should be given to children with diarrhoea.¹ Powders that claim to "bind" the stool have no proven value either.¹

Do probiotics help a child with diarrhoea?

The best recent trials say probably not. Two large trials in children's emergency departments, published in 2018, found that common probiotic products did not make stomach flu shorter or milder.^8,9

The IAP also found too little evidence to recommend probiotics for acute diarrhoea in India.² They are unlikely to harm, but they are not a substitute for ORS and zinc. Dr Dutta would rather families spend that money on fresh food.

How long does diarrhoea last in a child?

Diarrhoea from a stomach virus usually lasts 5 to 7 days and stops within 2 weeks in most children.⁴

Diarrhoea lasting 14 days or more is called persistent diarrhoea.¹ It needs a doctor's review, because the main risk then is weight loss and poor nutrition.¹ Keep your child home from school or creche until 48 hours after the last loose stool or vomit.⁴

What are the signs of dehydration in a child?

Watch for a child who is restless or unusually irritable, has sunken eyes, and drinks eagerly as if very thirsty.¹ Two or more of these signs mean some dehydration.¹

Other warning signs:

• When you gently pinch the skin of the tummy, it goes back slowly.¹
• Fewer wet nappies or less urine than usual.⁴
• Pale or mottled skin, or cold hands and feet.⁴

Signs of severe dehydration are a child who is very drowsy or hard to wake, drinks poorly or cannot drink, and whose skin pinch goes back very slowly.¹ That child needs hospital care at once.

Which children get dehydrated faster?

Babies under 1 year, especially those under 6 months, and babies born with low birth weight are at higher risk.⁴

Risk is also higher in a child who has passed more than 5 watery stools or vomited more than twice in the last 24 hours, or who cannot keep fluids down.⁴ A baby who has stopped breastfeeding during the illness is also at risk.⁴ Bring these children to a doctor early, before the signs appear.

How can I prevent diarrhoea in my child?

Rotavirus vaccine, clean water, handwashing with soap, and exclusive breastfeeding for the first 6 months prevent many episodes.

Rotavirus is a common cause of severe diarrhoea in babies. A Cochrane review found that the vaccines used in India, Rotavac and Rotasiil, each prevented about half of severe rotavirus diarrhoea in the first year of life, with no extra serious side effects.¹⁰ Rotavirus vaccine is part of India's free government (UIP) schedule. Wash hands after changing nappies and before cooking or feeding.⁴

When should I take my child with diarrhoea to a doctor or hospital?

Go to hospital now if your child shows signs of severe dehydration:¹

• Very sleepy, floppy or hard to wake.
• Unable to drink, or drinking very poorly.
• Skin pinch on the tummy goes back very slowly.

Cold hands and feet, or pale or mottled skin, also need hospital care at once.⁴

See a doctor the same day if your child has any of these:

• Sunken eyes, or passing much less urine than usual.^1,4
• Blood in the stool.¹
• Repeated vomiting so that nothing stays down, or green vomit.
• Many watery stools, fever, or eating and drinking poorly.¹
• Your baby is under 6 months old or had a low birth weight. These babies dry out more easily, so see a doctor early.⁴
• A swollen or very painful tummy.
• Diarrhoea for more than 14 days, or no improvement after 3 days.¹

And come if you are simply worried. A parent's sense that "this child is not right" is often correct.