Acute diarrhoea in children

Red Flags

Severe dehydration (lethargy, sunken eyes, very slow skin pinch, unable to drink) — emergency IV fluid resuscitation with Ringer's lactate; admission^[1]
Persistent vomiting, severe abdominal pain, bilious vomiting, blood in stool, or convulsions — investigate other cause; admit^[1]
Suspected cholera (rice-water stool, rapid dehydration, outbreak setting) — IV fluid + antibiotic; notify public health; isolate where possible^[1]
Persistent diarrhoea ≥14 days, weight loss, or failure to thrive — investigate for chronic infection, malabsorption, intolerance, immunodeficiency^[1]

First-line treatment

Interventions

Plan A — no dehydration (home)^[1]
Continue breastfeeding and age-appropriate feeding (do not stop or dilute milk); extra ORS after each loose stool (50–100 mL <2 years, 100–200 mL ≥2 years); zinc 14 days
Plan B — some dehydration (clinic)^[1]
Low-osmolarity ORS 75 mL/kg over 4 hours; reassess at 4 h. If improved, continue at home with Plan A. If unchanged, repeat. If worse, escalate to Plan C
Plan C — severe dehydration (admission)^[1]
Ringer's lactate IV: <12 months 30 mL/kg over 1 h then 70 mL/kg over 5 h. ≥12 months 30 mL/kg over 30 min then 70 mL/kg over 2.5 h. Reassess after each bolus
Continue feeding throughout illness^[1]
Breastfeeding continues uninterrupted. Older infants and children should resume normal diet as soon as tolerated; lactose-free formula not routinely needed except in protracted post-enteritis intolerance

First-line drug therapy

Drug	Class	Adult	Paediatric	Notes
Low-osmolarity ORS^[1]	Oral rehydration salt	Not applicable — paediatric guideline	Plan A: 50–100 mL <2 years, 100–200 mL ≥2 years after each stool. Plan B: 75 mL/kg over 4 h	Sodium 75 mEq/L, glucose 75 mmol/L, osmolarity 245 mOsm/L; continue with feeds, do not dilute or boil; replaces electrolytes and prevents dehydration
Zinc supplementation^[1]	Trace element	Not applicable — paediatric guideline	≥6 months: 20 mg PO daily × 14 days. <6 months: 10 mg PO daily × 14 days	Reduces severity, duration, and recurrence of diarrhoea; given as dispersible tablet; continue full 14 days even after diarrhoea stops
Ringer's lactate (IV)^[1]	Balanced isotonic crystalloid	Not applicable — paediatric guideline	Severe dehydration weight-based per IMNCI Plan C	Preferred over normal saline for severe dehydration; avoid over-hydration in malnourished children (different ORS scheme — ReSoMal — and slower rehydration)
Ciprofloxacin or azithromycin (selective)^[1]	Fluoroquinolone or macrolide	Not applicable — paediatric guideline	Ciprofloxacin 15 mg/kg BD × 3 days for shigellosis; azithromycin 10 mg/kg single dose for cholera	Only for visible blood in stool (probable shigellosis), suspected cholera, or culture-proven bacterial enteritis; avoid for non-specific diarrhoea (AMR)
Metronidazole (for amoebiasis or giardiasis)^[1]	Nitroimidazole	Not applicable — paediatric guideline	Amoebiasis: 35–50 mg/kg/day in 3 divided doses × 5–10 days. Giardiasis: 15 mg/kg/day × 5 days	Prolonged or persistent diarrhoea with confirmed amoebic or Giardia parasites on stool; not for routine use
DO NOT use anti-motility agents (loperamide) in children^[1]	Anti-motility agent — contraindicated	Not applicable	Contraindicated in children with diarrhoea	Risks paralytic ileus, sepsis, and delayed pathogen clearance; avoid antiemetics other than ondansetron in selected ED settings

Low-osmolarity ORS^[1]

Oral rehydration salt

Adult: Not applicable — paediatric guideline
Paediatric: Plan A: 50–100 mL <2 years, 100–200 mL ≥2 years after each stool. Plan B: 75 mL/kg over 4 h

Sodium 75 mEq/L, glucose 75 mmol/L, osmolarity 245 mOsm/L; continue with feeds, do not dilute or boil; replaces electrolytes and prevents dehydration

Zinc supplementation^[1]

Trace element

Adult: Not applicable — paediatric guideline
Paediatric: ≥6 months: 20 mg PO daily × 14 days. <6 months: 10 mg PO daily × 14 days

Reduces severity, duration, and recurrence of diarrhoea; given as dispersible tablet; continue full 14 days even after diarrhoea stops

Ringer's lactate (IV)^[1]

Balanced isotonic crystalloid

Adult: Not applicable — paediatric guideline
Paediatric: Severe dehydration weight-based per IMNCI Plan C

Preferred over normal saline for severe dehydration; avoid over-hydration in malnourished children (different ORS scheme — ReSoMal — and slower rehydration)

Ciprofloxacin or azithromycin (selective)^[1]

Fluoroquinolone or macrolide

Adult: Not applicable — paediatric guideline
Paediatric: Ciprofloxacin 15 mg/kg BD × 3 days for shigellosis; azithromycin 10 mg/kg single dose for cholera

Only for visible blood in stool (probable shigellosis), suspected cholera, or culture-proven bacterial enteritis; avoid for non-specific diarrhoea (AMR)

Metronidazole (for amoebiasis or giardiasis)^[1]

Nitroimidazole

Adult: Not applicable — paediatric guideline
Paediatric: Amoebiasis: 35–50 mg/kg/day in 3 divided doses × 5–10 days. Giardiasis: 15 mg/kg/day × 5 days

Prolonged or persistent diarrhoea with confirmed amoebic or Giardia parasites on stool; not for routine use

DO NOT use anti-motility agents (loperamide) in children^[1]

Anti-motility agent — contraindicated

Adult: Not applicable
Paediatric: Contraindicated in children with diarrhoea

Risks paralytic ileus, sepsis, and delayed pathogen clearance; avoid antiemetics other than ondansetron in selected ED settings

Safety-net

Continue breastfeeding and feeding through the illness — withholding food prolongs diarrhoea and worsens nutrition^[1]
Return same-day if child cannot drink, vomits everything, becomes lethargic, develops blood in stool, persistent fever, or fewer wet nappies than usual^[1]
Hand hygiene, safe drinking water, exclusive breastfeeding for 6 months, and rotavirus + measles vaccination prevent most childhood diarrhoea^[1]

Referral criteria

Severe dehydration, persistent vomiting, suspected sepsis, severe acute malnutrition with diarrhoeaPaediatric admission^[1]
Persistent diarrhoea ≥14 days or chronic diarrhoea with weight lossPaediatric review for malabsorption, immunodeficiency, post-enteritis enteropathy^[1]
Visible blood in stool with high fever or systemic illnessPaediatric admission for IV antibiotic and supportive care^[1]
Cluster of cases (suspected outbreak — cholera, rotavirus)Public health notification; contact tracing and water/sanitation review^[1]

Clinical summary

Triage of dehydration, low-osmolarity ORS, zinc, and selective antibiotic use in acute diarrhoeal disease in children under 5.

References

1.Indian Academy of Pediatrics Guidelines for Management of Acute Diarrhoea in Children (2022); WHO/UNICEF integrated diarrhoea management; IMNCI (2022)