Bile-stained (green) vomiting, blood in the stool, a tense abdomen, or lethargy: exclude a surgical abdomen (obstruction, intussusception, appendicitis) and sepsis. Do not use anti-motility or antiemetic drugs routinely in young children.
Grading dehydration
- No clinically detectable dehydration: under 5% loss, well
- Clinical dehydration: irritable, reduced urine, dry membranes, tachycardia, reduced skin turgor
- Shock (red flags): reduced consciousness, pale or mottled, cold peripheries, prolonged CRT, weak pulses, hypotension
- Highest risk: under 1 year, under 6 months, over 5 stools or over 2 vomits in 24 h
Fluids
- No or clinical dehydration: oral rehydration salts, little and often
- Shock: rapid IV 0.9% saline bolus (10 mL/kg), reassess, repeat; senior help
- IV fluid: replace deficit plus maintenance if ORS not tolerated or shocked
- Continue breastfeeding throughout
No clinical dehydration
- Alert, normal pulse and skin
- Continue feeding and fluids
- Safety-net advice
Clinical dehydration
- Irritable, sunken eyes, reduced urine
- Oral rehydration 50 mL/kg over 4 h
- Reassess regularly
Shock
- Reduced consciousness, mottled, cold
- Weak pulses, prolonged CRT
- 20 mL/kg bolus, senior help
Management
1
1. Rehydrate
ORS in small frequent amounts (consider via NG tube if refused). Reassess hydration regularly.
ORS in small frequent amounts (consider via NG tube if refused). Reassess hydration regularly.
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2
2. Feed
Resume the usual diet once rehydrated; continue breastfeeding. Avoid fruit juices and fizzy drinks.
Resume the usual diet once rehydrated; continue breastfeeding. Avoid fruit juices and fizzy drinks.
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3
3. Admit or escalate
Shock, deterioration, bilious vomiting or blood in stool, failed oral or NG rehydration, or significant comorbidity. Check U&E and glucose if IV fluids needed.
Shock, deterioration, bilious vomiting or blood in stool, failed oral or NG rehydration, or significant comorbidity. Check U&E and glucose if IV fluids needed.
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4
4. Prevent spread
Hand hygiene advice; stay away from nursery or school until 48 h after the last episode. Report notifiable causes.
Hand hygiene advice; stay away from nursery or school until 48 h after the last episode. Report notifiable causes.
Consider other diagnoses if
- Green bilious vomiting (obstruction)
- Blood or mucus with episodic pain and a mass (intussusception)
- Localised or severe abdominal pain or guarding
- High fever with few GI symptoms (sepsis, UTI, meningitis)
Pitfalls
- Mislabelling a surgical abdomen as gastroenteritis
- Routine antiemetics or anti-motility agents in young children
- Missing hypernatraemic dehydration (jittery, doughy skin)
- Under-estimating dehydration in a plump or febrile infant
MedPrep - www.medprep.uk - Educational revision aid only. Not clinical guidance. Doses are adult examples; check the BNF, current guidelines and local policy, and seek senior advice. Nov 2026