Diarrhoea is so common in India that it is often dismissed as a minor nuisance. But the numbers tell a different story: diarrhoeal diseases remain one of the top causes of death in children under five in India, responsible for approximately 13% of under-5 mortality. Most of these deaths are not caused by the diarrhoea itself — they are caused by the dehydration it produces, and by the failure to replace lost fluids correctly and promptly.
Oral Rehydration Solution (ORS) is one of the greatest life-saving discoveries in medical history. A simple solution of sugar, salt, and water — prepared in exactly the right proportions — can replace the fluids and electrolytes lost in diarrhoea and prevent the dehydration that kills. Since the WHO introduced ORS in the 1970s, it is estimated to have saved over 50 million lives.
This guide explains everything about ORS — how to prepare it, how much to give, when ORS alone is enough, and when a child needs IV fluids in a hospital.
Why ORS Works — The Science of Glucose-Sodium Cotransport
During diarrhoea, the gut loses the ability to absorb sodium and water through normal mechanisms. However, a specific transporter — the sodium-glucose cotransporter (SGLT1) — remains functional even in severe diarrhoeal illness. This transporter absorbs sodium and glucose together in a 1:1 ratio. When glucose is present in the gut alongside sodium, sodium absorption is dramatically enhanced, and water follows by osmosis.
This is why pure water does not effectively rehydrate a child with diarrhoea — there is no glucose to drive the cotransporter. And why sugary drinks like cola or fruit juice are counterproductive — they contain too much sugar and not enough sodium, worsening osmotic diarrhoea. ORS is precisely formulated to hit the optimal glucose-to-sodium ratio for maximum absorption.
WHO/UNICEF Low-Osmolarity ORS — The Correct Formula
⚠️ Always dissolve one ORS sachet in exactly 1 litre of water — not more, not less. Adding half a sachet to 500 mL or one sachet to 500 mL changes the electrolyte concentration and can be dangerous. Measure the water carefully.
How to Prepare ORS Correctly — Step by Step
- Use 1 litre of clean water. Boiled and cooled water is best. If boiling is not possible, use the cleanest water available — treated or filtered water. Do not use carbonated water or flavoured drinks.
- Open one ORS sachet (Electral or equivalent). Do not use two sachets for one litre — this over-concentrates the solution.
- Pour the entire sachet into the water and stir well until completely dissolved. The solution should be clear.
- Give in small, frequent sips. Do not give large volumes at once — this triggers vomiting. A teaspoon every 1–2 minutes in very young infants; small cups frequently in older children.
- Discard any unused ORS after 24 hours. Prepared ORS can become contaminated if stored. Prepare fresh batches daily.
Home-Made ORS — Emergency Use Only
If commercial ORS is not immediately available:
1 litre clean water + 6 level teaspoons of sugar + ½ teaspoon of common salt
This is a stopgap only. Obtain proper WHO-ORS sachets as quickly as possible — home-made ORS has less precise electrolyte content.
The WHO Treatment Plans — A, B, and C
Every diarrhoea patient is classified into one of three WHO treatment plans based on their degree of dehydration (assessed using the WHO 4-sign method: general appearance, eyes, thirst/drinking, and skin pinch).
Plan A
No / Minimal Dehydration
Home treatment with ORS. Continue normal feeding. Zinc 10–14 days.
Plan B
Some Dehydration
75 mL/kg ORS over 4 hours at a health facility. Reassess hourly.
Plan C
Severe Dehydration
IV Ringer's Lactate 100 mL/kg urgently. Hospital admission required.
💧 Use the RxMedCalc ORS Dose Calculator — enter weight and dehydration degree to get exact ORS volumes for Plan A and Plan B, plus zinc dosing by age.
ORS Doses by Weight and Age — Plan A and Plan B
| Age / Weight | Plan A: ORS per loose stool (ongoing losses) | Plan B: Total ORS over 4 hours |
|---|
| Infants < 6 months (< 5 kg) | 50 mL per loose stool | 200–400 mL total (75 mL/kg) |
| 6 months – 2 years (5–8 kg) | 50–100 mL per loose stool | 400–600 mL total |
| 2–10 years (8–20 kg) | 100–200 mL per loose stool | 600–1,200 mL total |
| Children > 10 years / Adults | 200–400 mL per loose stool | 2,000–4,000 mL as tolerated |
✅ If the child vomits while taking ORS: Wait 5–10 minutes, then restart more slowly — 5 mL (1 teaspoon) every 1–2 minutes. Vomiting is not a reason to stop ORS; small amounts given frequently are usually retained.
Plan B in Detail — Supervised Rehydration at a Health Facility
For a child with some dehydration (sunken eyes, drinking eagerly, skin pinch returns slowly in 1–2 seconds), the WHO Plan B protocol:
- Give 75 mL/kg of ORS over 4 hours at a health facility — by cup and spoon, not bottle
- Reassess dehydration signs every 1–2 hours during treatment
- If the child vomits repeatedly and cannot retain oral ORS → insert nasogastric tube and give ORS at 20 mL/kg/hour via NG
- After 4 hours: reassess — if rehydrated, switch to Plan A; if still some dehydration, repeat Plan B; if worsened, move to Plan C
- Continue breastfeeding throughout. Offer age-appropriate food once rehydrated.
Plan C — Severe Dehydration — Hospital Emergency
Severe dehydration (child lethargic or unable to drink, very sunken eyes, skin pinch returns very slowly >2 seconds) is a medical emergency requiring immediate IV access:
- Fluid: Ringer's Lactate (Hartmann's Solution) — preferred over normal saline. Never use 5% dextrose alone.
- Children ≥ 12 months: 30 mL/kg over 30 minutes, then 70 mL/kg over 2.5 hours
- Infants < 12 months: 30 mL/kg over 1 hour, then 70 mL/kg over 5 hours
- Reassess every 15–30 minutes. Start ORS (5 mL/kg/hour) as soon as the child can drink.
- Monitor blood glucose — hypoglycaemia is a risk, especially in malnourished infants.
Zinc Supplementation — Mandatory with ORS
WHO and IAP guidelines recommend zinc with every ORS course — it is not optional:
| Age Group | Zinc Dose | Duration | Formulation |
|---|
| Infants < 6 months | 10 mg/day | 10–14 days | Dispersible tablet or syrup (Zinconia, Zincovit) |
| Children ≥ 6 months | 20 mg/day | 10–14 days | Dispersible tablet or syrup |
| Adults | Not routinely recommended | — | Focus zinc supplementation on children under 5 |
Zinc reduces diarrhoea duration by approximately 25%, decreases stool frequency, and — crucially — reduces the risk of another diarrhoeal episode for the next 3 months. The 10–14 day course must be completed even after diarrhoea has stopped.
Do's and Don'ts During Diarrhoea
✅ DO These
- Continue ORS after every loose stool
- Continue breastfeeding — do not stop
- Continue age-appropriate feeding — do not withhold food
- Give zinc for 10–14 days
- Wash hands thoroughly with soap before and after nappy changes
- Use clean water to prepare ORS
- Discard unused ORS after 24 hours
❌ DON'T Do These
- Do not give cola, fruit juice, or glucose water instead of ORS
- Do not give loperamide (Imodium) to children — contraindicated, causes paralytic ileus
- Do not give antibiotics for watery diarrhoea — useless for viral causes
- Do not "starve" the child — withholding food prolongs diarrhoea
- Do not add extra salt or sugar to prepared ORS
- Do not give anti-vomiting drugs routinely — ORS given in small sips usually works
- Do not give undiluted cow's milk during active diarrhoea in young infants
⚠️ Cola and sports drinks are NOT substitutes for ORS. Cola has ~700 mOsm/L (vs 245 mOsm/L for ORS), negligible sodium, and high sugar — it worsens osmotic diarrhoea. Sports drinks have variable electrolyte content not calibrated for diarrhoeal losses. Use only properly formulated WHO-ORS.
When Antibiotics ARE Indicated for Diarrhoea
Most acute diarrhoea in children and adults is viral — antibiotics are useless and promote resistance. Antibiotics are indicated only for:
- Bloody diarrhoea (dysentery) — send stool culture; empirical azithromycin (10 mg/kg/day × 3 days in children) or ciprofloxacin in adults
- Suspected cholera — rice-water stools in an epidemic setting; doxycycline (single dose, adults) or azithromycin
- Proven Giardia or Entamoeba histolytica on stool microscopy — metronidazole 7–10 days
- Diarrhoea in a child < 3 months with fever — high risk of bacteraemia; requires full sepsis evaluation
- Severely malnourished children with any diarrhoea — standard protocol includes empirical antibiotics
Red Flags — When to Go to Hospital Immediately
- 🔴 Child is lethargic, limp, or unconscious
- 🔴 Unable to drink or keep ORS down despite giving slowly by spoon
- 🔴 Profuse, very frequent watery stools — more than 10 per day
- 🔴 Bloody stools or mucus in stool
- 🔴 High fever (> 39°C or > 38.5°C in infant < 3 months)
- 🔴 No urine passed for more than 6 hours
- 🔴 Sunken eyes, very dry mouth, skin pinch returns slowly
- 🔴 Any infant under 2 months with diarrhoea
- 🔴 Signs are not improving after 4 hours of correct ORS at home
- 🔴 Child appears to be getting worse, not better
Preventing Diarrhoea — The WASH Framework
In India, most childhood diarrhoea is preventable through the WASH framework — Water, Sanitation, and Hygiene:
- Water: Use treated, boiled, or filtered water for drinking and food preparation. Store water in clean covered containers.
- Sanitation: Use a toilet — open defecation is the primary source of faecal-oral pathogen transmission. The Swachh Bharat Mission has made significant progress but open defecation continues in many rural areas.
- Hygiene: Handwashing with soap is the single most effective intervention against diarrhoea transmission. Wash hands after using the toilet and before preparing food or feeding children.
- Breastfeeding: Exclusive breastfeeding for 6 months dramatically reduces diarrhoea incidence — breast milk contains IgA antibodies, lactoferrin, and oligosaccharides that protect the gut.
- Rotavirus vaccination: The most common cause of severe childhood diarrhoea is rotavirus — vaccination in the UIP schedule provides over 50% protection against severe rotavirus diarrhoea.
Key Takeaways
- ORS works via glucose-sodium cotransport (SGLT1) — not just fluid replacement. Composition matters critically.
- Always dissolve one sachet in exactly 1 litre of clean water — incorrect dilution is dangerous
- Plan A: 50–200 mL ORS per loose stool at home; Plan B: 75 mL/kg over 4h at facility; Plan C: IV RL 100 mL/kg urgently
- Zinc 10 mg/day (< 6 months) or 20 mg/day (≥ 6 months) for 10–14 days — reduces duration and recurrence
- Continue breastfeeding and feeding throughout — withholding food prolongs diarrhoea
- Loperamide is contraindicated in children — causes dangerous paralytic ileus
- Cola and juice are NOT ORS substitutes — they worsen osmotic diarrhoea
- Antibiotics only for bloody diarrhoea, cholera, proven bacterial cause — not for watery diarrhoea
- Go to hospital if: child cannot drink, is lethargic, has bloody stools, or is not improving after 4 hours
References
- World Health Organization. The treatment of diarrhoea: a manual for physicians and other senior health workers. 4th Revision. WHO, 2005.
- WHO/UNICEF. Joint Statement — Clinical management of acute diarrhea. 2004.
- Indian Academy of Pediatrics. IAP Guidelines on Management of Acute Diarrhea. Indian Pediatrics. 2016.
- Bhutta ZA et al. Therapeutic effects of oral zinc in acute and persistent diarrhea in children in developing countries: pooled analysis of randomized controlled trials. Am J Clin Nutr. 2000;72(6):1516-1522.
- Guerrant RL et al. Practice guidelines for the management of infectious diarrhea. Clin Infect Dis. 2001;32(3):331-351.
This article is for educational purposes based on WHO IMCI and IAP 2024 guidelines. ORS and zinc are first-line treatment for mild-to-moderate diarrhoea. Severe dehydration requires immediate medical care — do not attempt home treatment alone if red flag signs are present.
Built by an MBBS, AFIH Certified Physician in Punjab, India | RxMedCalc.com