Children with a tummy bug should be given watered down apple juice, a study found.
Gastroenteritis is a very common condition in children causing diarrhoea and vomiting mostly caused by the virus rotavirus.
Most cases are mild and pass within five to seven days without any specific treatment.
However young children particularly the under one's are at risk of dehydration, so they should be given plenty of fluids or in some cases special oral rehydration solutions to replace lost sugar and salts.
In rare cases they need to go to hospital to be put on an intravenous drip.
But children with mild gastroenteritis and minimal dehydration responded better if given a glass of half-strength apple juice along with other fluids than oral rehydration solutions.
They were less likely to need a drip, go to hospital or visit the family doctor again, have protracted symptoms or suffer three per cent or more weight loss or significant dehydration in the next seven days.
Diluted apple juice is not only cheaper but tastier too with children over two benefiting the most, University of Calgary scientists said.
The study gave watered down apple juice or apple-flavoured electrolyte maintenance solution to 647 children aged six to 60 months with gastroenteritis.
It then analysed if the child needed follow up treatment or still had symptoms that would not go away over the next seven days.
It found the children given the diluted apple experienced treatment failure less often than those given electrolyte maintenance solution - 17 per cent compared to 25 per cent.
They were less likely to be put on a drip - 2.5 per cent compared to 9 per cent.
Rates of being admitted to hospital or how often they had diarrhoea and vomiting were not significantly different between groups.
Associate Professor Dr Stephen Freedman said: "Paediatric gastroenteritis therapy is focused on oral rehydration solution administration to prevent and treat dehydration whenever diarrhoea occurs.
"Evidence supporting this approach has emerged primarily from low- and middle-income countries.
"Similar benefits may not arise from routine electrolyte maintenance solution administration in locations where significant dehydration is uncommon.
"Children with mild gastroenteritis and minimal dehydration experienced fewer treatment failures when offered dilute apple juice followed by their preferred fluid choice compared with those instructed to drink electrolyte maintenance solution to replace fluid losses.
"The benefit was greatest among children older than 24 months.
"Dilute apple juice administration followed by desired fluids resulted in a reduction in the intravenous rehydration rate.
"In many high-income countries, the use of dilute apple juice and preferred fluids as desired may be an appropriate alternative to electrolyte maintenance fluids in children with mild gastroenteritis and minimal dehydration."
The study was published online by JAMA.