Diarrhoea and vomiting in a baby
A child with diarrhoea dies of lost water and salt, not of the infection. Four bedside signs tell you how dry the child is, and the answer decides the plan: home, four hours of ORS in the clinic, or urgent rehydration.
- Setting: Health post in a settlement for displaced families, no malaria transmission, no IV fluids on site
- For nurses, clinical officers, doctors and community health workers trained in IMCI
- Reviewed October 2026
The presentation
Yusuf, 10 months old, has had watery diarrhoea for 2 days, about eight times a day, and has vomited three times since this morning. He is breastfed and also eats porridge. His mother has been giving him water from a bottle. He weighs 8 kg.
| Sign | Value |
|---|---|
| Axillary temperature | 37.4 °C |
| Breathing rate | 38 per minute |
| Pulse | 148 per minute |
| Conscious level (AVPU) | Alert, crying and restless |
| Weight | 8 kg |
Tests at hand: Mid-upper arm circumference (MUAC) · Blood glucose (finger-prick) · Malaria rapid diagnostic test (RDT)
- Acute watery diarrhoea (usually viral)Still possible
- Severe dehydration Must not missStill possible
- Cholera Must not missStill possible
- Dysentery (blood in the stool)Still possible
- Severe infection with diarrhoea (sepsis, malaria, pneumonia) Must not missStill possible
- Severe acute malnutrition with diarrhoea Must not missStill possible
- Persistent diarrhoeaLess likely
Work through it
Read each question and decide your own answer first. Then open the model answer and see how the differential changes.
- Step 1 of 7 · Look
Is Yusuf an emergency? Which signs do you check first?
Model answer
Emergency signs first: airway and breathing, shock (cold hands, capillary refill longer than 3 seconds, weak fast pulse), coma or convulsions, and severe dehydration (lethargy, sunken eyes, very slow skin pinch). Then the four IMCI general danger signs: not able to drink or breastfeed, vomits everything, convulsions, lethargic or unconscious.
He has vomited, but not everything: he breastfed 20 minutes ago and kept it down. He is restless and crying, not lethargic. His hands are warm and capillary refill is under 2 seconds.
No emergency sign and no general danger sign. Assess him fully now, in order.
Differential now- Acute watery diarrhoea (usually viral)Still possible
- Severe dehydration Must not missStill possible
- Cholera Must not missStill possible
- Dysentery (blood in the stool)Still possible
- Severe acute malnutrition with diarrhoea Must not missStill possible
- Severe infection with diarrhoea (sepsis, malaria, pneumonia) Must not missLess likely (moved down)
- Persistent diarrhoeaLess likely
- Step 2 of 7 · Ask
What do you ask about the diarrhoea, and why?
Model answer
- For how long? 14 days or more is persistent diarrhoea.
- Is there blood in the stool? (dysentery)
- How many stools and vomits, and is he passing urine?
- What has he been given to drink and eat, and is he still breastfeeding?
- Are other people in the settlement ill with sudden profuse watery diarrhoea? (a cholera outbreak)
- The other main symptoms: cough or difficult breathing, fever, ear problem.
Two days, no blood. He passed a little urine this morning. Breastfeeding and plain water from a bottle. No cholera cases reported in the settlement this month. No cough, no fever, no ear problem.
Differential now- Acute watery diarrhoea (usually viral)Leading (moved up)
- Severe dehydration Must not missStill possible
- Severe acute malnutrition with diarrhoea Must not missStill possible
- Cholera Must not missLess likely (moved down)
- Severe infection with diarrhoea (sepsis, malaria, pneumonia) Must not missLess likely
- Dysentery (blood in the stool)Set aside for now (moved down)
- Persistent diarrhoeaSet aside for now (moved down)
- Step 3 of 7 · Look
Grade his dehydration. Which four signs do you look at, and what do you find?
Model answer
Two signs in a column are enough for that classification. Sign Severe dehydration Some dehydration Yusuf General condition Lethargic or unconscious Restless, irritable Restless, irritable Eyes Sunken Sunken Sunken Offer a drink Not able to drink, or drinking poorly Drinks eagerly, thirsty Drinks eagerly from a cup Skin pinch (abdomen) Goes back very slowly (longer than 2 seconds) Goes back slowly Goes back slowly He has four signs in the middle column: some dehydration.
Differential now- Acute watery diarrhoea (usually viral)Leading
- Severe acute malnutrition with diarrhoea Must not missStill possible
- Severe dehydration Must not missLess likely (moved down)
- Cholera Must not missLess likely
- Severe infection with diarrhoea (sepsis, malaria, pneumonia) Must not missLess likely
- Dysentery (blood in the stool)Set aside for now
- Persistent diarrhoeaSet aside for now
- Step 4 of 7 · Test
Which of your tests do you need? What else must you check before you choose a plan?
Model answer
- MUAC and oedema of both feet: a child with severe acute malnutrition and diarrhoea is rehydrated differently and more slowly. Do not miss it.
- Malaria RDT: not needed. There is no malaria transmission here, he has no fever and has not travelled.
- Glucose: not needed while he is alert and feeding. Check it if he becomes lethargic or has a fit.
MUAC 131 mm, no oedema.
Differential now- Acute watery diarrhoea (usually viral)Leading
- Severe dehydration Must not missLess likely
- Cholera Must not missLess likely
- Severe infection with diarrhoea (sepsis, malaria, pneumonia) Must not missLess likely
- Dysentery (blood in the stool)Set aside for now
- Severe acute malnutrition with diarrhoea Must not missSet aside for now (moved down)
- Persistent diarrhoeaSet aside for now
- Step 5 of 7 · Do
Classify him and start treatment. How much ORS, over how long, and how is it given?
Model answer
Classification: some dehydration, acute watery diarrhoea, no danger sign, no other severe classification. Treat with Plan B in the clinic.
- ORS over 4 hours: for 6 to under 10 kg, 450 to 800 mL; or weight (kg) x 75 mL: 8 x 75 = 600 mL. Give more if he wants more.
- His mother gives small, frequent sips from a cup or spoon. If he vomits, wait 10 minutes, then continue more slowly.
- She keeps breastfeeding whenever he wants.
- Zinc: one 20 mg tablet a day for 14 days (from 6 months), dissolved in a little breast milk or ORS. The first dose now.
No antibiotic and no anti-diarrhoea or anti-vomiting medicine for acute watery diarrhoea in a young child.Differential now- Acute watery diarrhoea (usually viral)Leading
- Cholera Must not missLess likely
- Severe infection with diarrhoea (sepsis, malaria, pneumonia) Must not missLess likely
- Severe dehydration Must not missSet aside for now (moved down)
- Dysentery (blood in the stool)Set aside for now
- Severe acute malnutrition with diarrhoea Must not missSet aside for now
- Persistent diarrhoeaSet aside for now
- Step 6 of 7 · Look
Four hours later, you reassess. What do you look for, and what do you do with each result?
Model answer
- Signs of severe dehydration now: he needs Plan C. With no IV here, refer urgently, with his mother giving ORS sips on the way, unless you are trained to give ORS by nasogastric tube.
- Still some dehydration: repeat Plan B for another 4 hours and start offering food.
- No dehydration: go to Plan A and send him home.
- If his mother must leave before the 4 hours are up: show her how to make ORS, give her enough to finish the rehydration at home, and explain Plan A.
After 4 hours and 650 mL of ORS, Yusuf is calm, his eyes are no longer sunken, he drinks normally and the skin pinch goes back immediately. He has passed urine. No dehydration.
- Step 7 of 7 · Ask
He is going home. What does his mother need to know?
Model answer
- Plan A: after each loose stool, give 50 to 100 mL of ORS (he is under 2 years). Give her 2 packets and show her how to mix one in the right amount of clean water.
- Keep breastfeeding, more often and for longer. Use a cup, not a bottle. Continue his usual food.
- Finish all 14 days of zinc, even when the diarrhoea stops.
- Come back at once if he cannot drink or breastfeed, becomes sicker, develops a fever, drinks poorly, or has blood in the stool.
- Come back in 5 days if the diarrhoea is not better.
- Hand washing with soap, and safe water storage.
His body was dry. The drink has put the water back. Give him a cup of this drink after every loose stool, keep breastfeeding, and give one zinc tablet each day for two weeks. Come back straight away if he cannot drink, gets sicker, has a fever or blood in his stool.
Must-not-miss conditions
| Condition | Clues | What to do at first-level care |
|---|---|---|
| Severe dehydration or shock | Two of: lethargic or unconscious, sunken eyes, not able to drink or drinking poorly, skin pinch going back very slowly; cold hands, slow capillary refill, weak pulse. | Plan C. No IV on site: refer urgently with ORS sips on the way, or nasogastric ORS if trained. |
| Cholera | Profuse watery diarrhoea in a known cholera area or outbreak, often with vomiting and fast dehydration. | Rehydrate by plan; in a cholera area, a child of 2 years or older with severe dehydration also gets an antibiotic for cholera; report and follow outbreak measures. |
| Severe acute malnutrition with diarrhoea | MUAC below 115 mm, or oedema of both feet. | Do not use the standard plans; refer, or rehydrate slowly with the malnutrition protocol. |
| Dysentery | Blood in the stool. | Ciprofloxacin for 3 days, rehydrate, review in 3 days; refer a young infant or a child who is not improving. |
| Another severe illness | Fever in a malaria area, fast breathing, stiff neck or a danger sign. | Classify and treat each problem; refer if any severe classification. |
Decision at first-level care
Yusuf had some dehydration from acute watery diarrhoea, with no danger sign, no blood in the stool and no malnutrition. He stayed in the clinic for 4 hours of Plan B ORS with zinc, and at reassessment had no dehydration. He goes home on Plan A with zinc for 14 days and return advice.
Source: WHO IMCI chart booklet (2014); WHO Pocket book of hospital care for children (2013).
- No dehydration: Plan A and zinc at home, review in 5 days if not improving.
- Dysentery without danger signs: ciprofloxacin, fluids, review in 3 days.
- Some dehydration: Plan B ORS in the clinic for 4 hours, zinc, then reassess and choose the plan again.
- Still some dehydration after 4 hours: repeat Plan B and start food.
- Severe dehydration when you cannot give IV or nasogastric fluids, or with another severe classification.
- Any general danger sign.
- Diarrhoea for 14 days or more with dehydration.
- Severe acute malnutrition with diarrhoea.
- Not improving on Plan B.
Key learning points
- Grade dehydration with four signs: general condition, eyes, thirst and skin pinch. Two signs in a column are enough.
- Some dehydration is treated in the clinic with ORS over 4 hours (about 75 mL/kg), then reassessed.
- Zinc for 14 days and continued breastfeeding are part of the treatment.
- Check MUAC and oedema before choosing a plan: malnourished children are rehydrated differently.
- No antibiotics for acute watery diarrhoea unless there is blood in the stool or cholera with severe dehydration.
Sources
- World Health Organization. Integrated Management of Childhood Illness (IMCI) chart booklet. 2014. Dehydration classification; Plans A, B and C; ORS volumes; zinc dosing; cholera antibiotic rule; dysentery; persistent diarrhoea; when to return; follow-up in 5 days.
- World Health Organization. Pocket book of hospital care for children: guidelines for the management of common childhood illnesses, second edition. 2013. Emergency signs including severe dehydration; skin pinch longer than 2 seconds as very slow; no anti-diarrhoeal or anti-emetic medicines in young children.
- World Health Organization. Guideline on management of pneumonia and diarrhoea in children up to 10 years of age. 2024. Low-osmolarity ORS and zinc as the basis of diarrhoea care.
- 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. Different rehydration in children with severe wasting.