Diarrhoea and dehydration in a child under 5 (IMCI)
WHO IMCI · reviewed October 2026 · gpreasoning.uk/global
Reasoning GP
Global Primary Care
Who / when
- Children aged 2 months up to 5 years with diarrhoea (three or more loose or watery stools in 24 hours).
- Young infants under 2 months: use the sick young infant protocol.
- Child with severe acute malnutrition and diarrhoea: rehydrate differently (ReSoMal or careful ORS); refer.
Red flags: refer now
- Any general danger sign: not able to drink or breastfeed, vomits everything, convulsions, lethargic or unconscious.
- Severe dehydration when you cannot give IV fluid or a nasogastric drip.
- Severe dehydration plus another severe classification.
- Severe acute malnutrition, or blood in stool in an infant under 12 months who is not improving.
Sips of ORS all the wayRefer urgently with the mother giving frequent sips of ORS on the way, and keep breastfeeding.
Assess
- Ask: for how long? Is there blood in the stool?
- Look: is the child lethargic or unconscious, or restless and irritable? Are the eyes sunken?
- Offer a drink: not able to drink or drinking poorly, or drinking eagerly and thirsty?
- Pinch the skin of the abdomen: does it go back very slowly (more than 2 seconds) or slowly?
- Check weight, nutritional status (MUAC) and other illness (fever, cough, measles).
Classify
| Signs | Classify as | Plan |
|---|
| Two of: lethargic or unconscious; sunken eyes; not able to drink or drinking poorly; skin pinch goes back very slowly | Severe dehydration | Plan C (or refer urgently if another severe classification). Cholera area and age 2 years or over: antibiotic for cholera |
| Two of: restless, irritable; sunken eyes; drinks eagerly, thirsty; skin pinch goes back slowly | Some dehydration | Plan B, zinc, food; follow up in 5 days if not improving |
| Not enough signs for some or severe | No dehydration | Plan A, zinc; follow up in 5 days if not improving |
- 14 days or more: with dehydration, severe persistent diarrhoea (treat dehydration, refer); without, persistent diarrhoea (feeding advice, multivitamins and minerals including zinc for 14 days, review in 5 days).
- Blood in the stool: dysentery: ciprofloxacin 15 mg/kg twice daily for 3 days; review in 3 days.
Treat
Plan A: treat at home
- Extra fluid: after each loose stool, 50 to 100 mL under 2 years; 100 to 200 mL from 2 years. Give 2 packets of ORS to take home.
- Zinc 20 mg tablet daily for 14 days: half a tablet from 2 to 6 months; one tablet from 6 months. Dissolve for infants.
- Continue feeding (exclusive breastfeeding under 6 months). Explain when to return.
Plan B: ORS in the clinic over 4 hours
Or weight (kg) x 75 mL. Give more if the child wants it. Small frequent sips from a cup; if the child vomits, wait 10 minutes, then continue more slowly. Reassess after 4 hours and choose the plan again.| Weight | Under 6 kg | 6 to under 10 kg | 10 to under 12 kg | 12 to 19 kg |
|---|
| ORS in 4 hours | 200 to 450 mL | 450 to 800 mL | 800 to 960 mL | 960 to 1600 mL |
Plan C: severe dehydration
- IV possible: Ringer's lactate (or normal saline) 100 mL/kg. Under 12 months: 30 mL/kg in 1 hour, then 70 mL/kg in 5 hours. 12 months to 5 years: 30 mL/kg in 30 minutes, then 70 mL/kg in 2.5 hours. Repeat the first part once if the radial pulse is still very weak. Give ORS (about 5 mL/kg/hour) as soon as the child can drink.
- No IV but IV within 30 minutes: refer urgently, sips of ORS on the way.
- Trained in nasogastric rehydration: ORS 20 mL/kg/hour for 6 hours (120 mL/kg); reassess every 1 to 2 hours.
- Observe at least 6 hours after rehydration before sending home.
Follow-up
- Dysentery after 3 days: fewer stools, less blood, less fever and pain, eating better: finish ciprofloxacin. Same or worse: second-line antibiotic or refer; under 12 months, dehydrated at first visit, or measles in last 3 months: refer.
- Persistent diarrhoea after 5 days: stopped: usual feeding. Not stopped (3 or more loose stools a day): reassess and refer.
- Some or no dehydration: review in 5 days if not improving.
Counsel
- The four rules: extra fluid, zinc for the full 14 days, keep feeding, and know when to return.
- Mix ORS with the right amount of clean water; make fresh each day.
- Return at once if the child cannot drink or breastfeed, becomes sicker, develops a fever, has blood in the stool, or is drinking poorly.
- Handwashing with soap, safe water and safe stool disposal prevent the next episode.
Give this ORS drink after every loose stool and keep breastfeeding. Give one zinc tablet every day for 14 days, even after the diarrhoea stops. Come back at once if she cannot drink, gets sicker or has blood in the stool.
When to refer
- Urgently: severe dehydration you cannot treat (no IV or NG); severe dehydration with another severe classification; any general danger sign.
- Severe persistent diarrhoea (after rehydration).
- Dysentery not improving, or in a young child at higher risk.
- Severe acute malnutrition with diarrhoea.
- Not improving on Plan B after 4 hours.
Sources
World Health Organization. Integrated Management of Childhood Illness (IMCI) chart booklet. 2014. World Health Organization. Guideline on management of pneumonia and diarrhoea in children up to 10 years of age. 2024. World Health Organization. WHO guideline on the prevention and management of wasting and nutritional oedema (acute malnutrition) in infants and children under 5 years. 2023.Adapted from WHO guidance; not endorsed by WHO. This page paraphrases and adapts the WHO publications listed under Sources, which are licensed CC BY-NC-SA 3.0 IGO; the adapted text is shared under the same licence for non-commercial education. Reasoning GP is not affiliated with WHO or any other organisation named here. Use it alongside your national guidelines, essential medicines list and formulary, and your clinical judgement. Doses are given only where they come from a WHO source; otherwise follow your national guideline or formulary.