Clinical investigations from the RACP

Investigating the child with acute diarrhoea

Katie Frith, Elizabeth J Elliott



Most acute diarrhoea in childhood is caused by a self-limiting viral or bacterial illness. Identification of the pathogen causing diarrhoea is not always necessary, although in some circumstances a specific diagnosis should be sought to guide management.

Key Points

  • Acute diarrhoea is common in children and usually infective. Rotavirus infection is the most common cause.
  • Investigations are not usually required for acute diarrhoea because the condition is mostly self-limiting.
  • The majority of children with acute diarrhoea can be treated at home with oral fluids.
  • Dehydration associated with acute diarrhoea can be prevented with appropriate treatment.
  • Severely dehydrated children require hospital admission for enteral or intravenous fluid rehydration.
  • Antibiotics, antiemetic and antidiarrhoeal agents are rarely required and may have adverse effects in children.
  • Vaccination with the new rotavirus vaccine should be recommended for all babies commencing at 2 months of age.