Diagnosis

• Suspect gastroenteritis if sudden change in stool consistency, diarrhoea usually last 5-7 days, stops within 2 wks, Vomiting usually lasts 1-2 days, stops within 3 days
• Consider alternate diagnoses to gastroenteritis
  • > 38 deg < 3mths, >39 deg > 3 mths
  • Altered consciousness, neck stiffness, non-blanching rash
  • Bilious green vomit, severe or localised abdominal pain, distention of rebound tenderness

Dehydration status:

Hypernatreamia

• Hyper-reflexia
• Drowsiness
• Convulsions

Investigation

• Stool micro-biology if:
  • Child returned from abroad
  • Not improved in 7 days
  • Septicaemia
  • Immunocompromised
  • Blood / Mucus in stool
• Blood culture if giving antibiotics
• U+E + glucose if suspect hypernatraemia

Management

Not dehydrated:

• Continue breastfeeding, encourage fluid intake, but not carbonated or fruit juices

Dehydrated:

• ORS solution (low Osm 240-250) unless IV therapy indicated 50 ml/kg for deficit over 4 hrs plus maintenance, give frequently in small amounts, via nasogastric tube as necessary
• IV therapy 20 ml/kg 0.9% Sodium chloride, if shock is suspected of confirmed, or if child with red flags is deteriorating
• If remains shocked give another 20 ml/kg and consider other cause of shock, if no response consider child ICU

Rehydration:

• 100 ml/kg for those requiring rapid boluses for shock or 50 ml/kg for those not shocked on presentation and measure U+Es giving K+ as required
• If hypernatraemic give 0.9% sodium chloride slowly, typically 48 hrs, switching to ORS when tolerated
• After rehydration encourage breast feeding / fluid intake, or ORS 5 ml/kg if watery stool
• During rehydration, do not give solid food. Reintroduce once hydrated
• Only give antibiotics if septicaemia, < 6mths (or immunocompromised) with Salmonella gastroenteritis

NICE Source: CG84 Diarrhoea and vomiting caused by gastroenteritis in under 5s: diagnosis and management. Summary compiled by Dr D P Sheppard MBBS.