The National Institute for Health and Clinical Excellence (NICE) has drawn up new guidance for treating the condition, which can lead to severe kidney damage.
An estimated 82,000 children develop urinary tract infections each year.
Learning to hold urine in is thought to be one of the causes of infection so children, according to NICE, should “no longer be expected to wait”.
Signs that a child may have a UTI include needing to go the toilet frequently, pain when they go, tummy pain and unpleasant smelling urine.
This may be accompanied by more general symptoms such as fever, vomiting, tiredness and irritability, and these are what parents and doctors should look for in infants and very young children who cannot explain the kind of discomfort they are in.
Babies and children who have an unexplained fever of 38ºC or higher should have a urine sample tested within 24 hours.
NICE is providing this advice for doctors, but it also wants parents to be more aware of UTIs in children.