Diarrhoea and sickness in children - Diagnosing gastroenteritis in children

In most cases of gastroenteritis, a diagnosis is not needed. Your child's symptoms should disappear in around five to seven days, without specific treatment.

A diagnosis is usually only needed in certain situations, such as:

• if your child has recently been abroad to an area where they could have picked up a more serious type of infection caused by a parasite
• if their diarrhoea has not improved after seven days
• if they show signs and symptoms that are not usually associated with gastroenteritis
• if there is blood or mucus in their stools
• if they have a weakened immune system caused by an underlying health condition, such as acute leukaemia, or as a side effect of a medical treatment, such as chemotherapy

A diagnosis of gastroenteritis is based on the symptoms your child is having, although there may be some instances where a stool (faeces) sample is sent to a laboratory, so it can be checked for viruses, bacteria or parasites.

In some cases, a blood test or urine test may also be used to rule out other conditions, such as pneumonia or a urinary tract infection.