Diarrhoea kills mostly by drying the body out — draining the water and salts the body runs on — not usually by the infection itself. For a long time the only fast fix was an intravenous drip, which needs a clinic, sterile kit and trained hands. Then researchers found that a simple sugar helps the gut keep absorbing water and salt even during illness, so a person can often drink their way out of dehydration instead. The drink costs a few cents and almost anyone can give it — but the amounts matter, so this entry leads with when ORS is not enough.
At a glance — Origin: proven in Dhaka, Bangladesh (the Cholera Research Laboratory, now icddr,b) and in the 1971 refugee camps · Maturity: Scaled — the global standard of care for decades · Effort: a few cents and a little time, but clean water and the right measure are essential · Licence: open — WHO and UNICEF publish the formula and the home recipe free.
How it works. A balanced mix of salt, sugar and clean water, drunk in small frequent sips, replaces what diarrhoea drains away while the illness runs its course. The safest form is a ready-made ORS sachet dissolved in exactly the volume of clean water printed on it — the balance is already right, so nothing can go wrong but the water. Where no sachet is available, the home fallback is six (6) level teaspoons of sugar and half (½) a level teaspoon of salt in one litre (1 L) of clean or boiled water, stirred until dissolved; it should taste no saltier than tears, and if it is saltier, throw it out and make it again. For a child, give zinc alongside — twenty (20) mg a day for 10 to 14 days, or ten (10) mg a day for an infant under six months — and keep feeding and breastfeeding throughout.
What to expect — and what it does NOT do. Severe dehydration and shock need a drip, not a cup — this comes first, because the mistake is fatal. A child who is floppy or unconscious, whose eyes are sunken, who cannot drink, or who shows signs of shock needs intravenous fluids and a health facility immediately; ORS by mouth is not enough, and waiting to find one can kill. The same is true of relentless vomiting that keeps nothing down. Too much salt is genuinely dangerous — the reason for the taste test and for preferring a pre-measured sachet — and an over-salted mix can, in extreme cases, cause convulsions in infants. ORS rehydrates; it does NOT cure the infection or stop the diarrhoea, which keeps coming until the illness passes — that is normal and not a sign it is failing (historically, that is exactly why it was underused). And it must be made with clean water, or it carries the infection in with it. When in doubt, get medical help.
Who made it. A chain of people, not one genius: Robert K. Crane, who explained how glucose lets the gut absorb salt and water; David Nalin, Richard Cash, Norbert Hirschhorn and the Cholera Research Laboratory team in Dhaka, now icddr,b, who proved it clinically; and Dr Dilip Mahalanabis, whose use of a simple salt-sugar drink in the 1971 refugee camps cut cholera deaths from about 30% to under 4% where drips had run out.
Used ORS for a child or yourself — a sachet, or mixed at home? Tell us how it went — whether you had a sachet or made it, whether it kept the person hydrated, whether you needed to get to a clinic anyway, what you’d change, and roughly where and when. We want the honest result, including what didn’t work. Your contact details stay private; we read and check every report before anything is published, and we’ll never publish a detail you’ve asked us to keep private.
Sources: WHO’s diarrhoeal-disease fact sheet and the WHO/UNICEF Oral Rehydration Salts formula and clinical guidance (who.int); the Rehydration Project home-ORS recipe and the “no saltier than tears” check (rehydrate.org); the U.S. CDC’s guidance on managing acute gastroenteritis in children (cdc.gov); the 1971 case-fatality drop (about 30% → 3.6%) and the lives-saved estimates from Our World in Data (ourworldindata.org); history from icddr,b (icddrb.org).
