What criteria should I use to decide whether to refer a patient with gastroenteritis for specialist evaluation?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025Updated: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

To determine whether to refer a patient with gastroenteritis for specialist evaluation, consider the following criteria, which vary for adults and children:

  • For Adults (aged 16 years and over):
    • Arrange emergency hospital admission if:
      • The person is systemically unwell and/or has clinical features suggesting severe dehydration and/or progression to shock .
      • There is intractable vomiting or high-output diarrhoea .
      • There is a suspected serious complication, such as sepsis .
    • Consider arranging hospital assessment (urgency depending on clinical judgement) if:
      • There are clinical features suggesting a potentially life-threatening or serious alternative diagnosis .
      • There is an inadequate response to oral rehydration salt (ORS) solution, the person is unable to take ORS orally, or they are clinically deteriorating .
      • There are risk factors for developing dehydration, such as in the elderly, immunocompromised individuals, or those with co-morbid conditions or concurrent illness .
      • The person or carers are unable to provide appropriate management safely at home .
    • Liaise with a microbiologist or consultant in communicable disease control if:
      • There is uncertainty about the need for admission in a person with a confirmed microbiological cause on stool culture and sensitivity testing .
      • There is uncertainty about the need for management in a person with moderate or severe suspected travellers' diarrhoea .
      • There is a confirmed microbiological cause (e.g., Campylobacteriosis with severe symptoms/immunocompromise, or Cryptosporidiosis in severely immunocompromised individuals) and uncertainty about antibiotic treatment or microbiological clearance .
    • Refer if the diagnosis remains uncertain after a primary care assessment, especially if infection and other common causes of acute diarrhoea have been excluded and a chronic cause is suspected .
    • Consider a suspected cancer pathway referral for colorectal cancer if specific criteria related to diarrhoea and other symptoms are met (e.g., positive faecal immunochemical test (FIT) with unexplained weight loss, rectal bleeding, change in bowel habit, iron deficiency anaemia, or a rectal/abdominal mass) .
  • For Children (from 1 month to 15 years, including under 5s):
    • Arrange emergency hospital admission if:
      • The child is systemically unwell and/or has clinical features suggesting severe dehydration and/or progression to shock ,.
      • There is intractable or bilious vomiting .
      • There is acute-onset painful, bloody diarrhoea in previously healthy children, or confirmed Shiga toxin-producing Escherichia coli (STEC) infection 0157 .
      • There is a suspected serious complication, such as haemolytic uraemic syndrome or sepsis .
    • Consider arranging hospital assessment or referral to secondary care if:
      • There are clinical features suggesting a potentially life-threatening or serious alternative diagnosis (e.g., fever of 38°C or higher in children younger than 3 months, or 39°C or higher in children aged 3 months or older; shortness of breath; altered conscious state; neck stiffness; bulging fontanelle; non-blanching rash; blood and/or mucus in stool; bilious vomit; severe or localised abdominal pain; abdominal distension or rebound tenderness) ,.
      • There is an inadequate response to oral rehydration salt (ORS) solution, or the child is unable to take ORS orally ,.
      • There are red flag symptoms or signs suggesting increased risk of progression to shock, and the child is clinically deteriorating despite ORS ,.
      • There are risk factors for developing dehydration (e.g., children younger than 1 year, particularly those younger than 6 months; low birth weight infants; more than five diarrhoeal stools or more than twice vomiting in the previous 24 hours) ,.
      • The parents or carers are unable to monitor the child's condition or provide appropriate management safely at home, or social circumstances require continued healthcare professional involvement ,.
    • Liaise with a microbiologist or consultant in communicable disease control if:
      • There is uncertainty about the need for admission in a child with a confirmed microbiological cause on stool culture and sensitivity testing .
      • There is uncertainty about the need for management in a child with moderate or severe suspected travellers' diarrhoea .
    • Seek specialist advice about antibiotic therapy for children who have recently been abroad .
    • Obtain urgent expert advice on fluid management if intravenous fluid therapy is required in a child presenting with hypernatraemic dehydration .

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Educational content only. Always verify information and use clinical judgement.