Diarrhoea is a major killer in the developing world
An international initiative has been launched to cut the number of children who die from diarrhoea around the world.
The World Health Organization and UNICEF said urgent action was needed to combat a condition which kills an estimated 1.5m children a year.
They have drawn up a seven-point plan to tackle the problem, which is published in The Lancet.
It includes zinc treatment, promotion of breastfeeding and vaccinations.
SEVEN POINT PLAN
Fluid treatment to prevent dehydration
Rotavirus and measles vaccinations
Promotion of breastfeeding and vitamin A supplementation
Promotion of handwashing with soap
Improved water supply
Community-wide sanitation programme
Diarrhoea is not a significant cause of death in developed countries, but is a major problem in the developing world.
It is estimated that one in every five child deaths worldwide is due to diarrhoea - more than the child death toll from Aids, malaria and measles combined.
Ann Veneman, UNICEF executive director, said: "It is a tragedy that diarrhoea, which is little more than an inconvenience in the developed world, kills an estimated 1.5m children each year.
"Inexpensive and effective treatments for diarrhoea exist, but in developing countries only 39% of children with diarrhoea receive the recommended treatment."
Dr Margaret Chan, Director-General of WHO, said: "We know where children are dying of diarrhoea.
"We know what must be done to prevent those deaths. We must work with governments and partners to put this seven-point plan into action."
Campaigns targeting childhood diarrhoea in the 1970s and 1980s achieved success by scaling up the use of oral rehydration solution (ORS) to prevent dehydration and by educating caregivers.
However, the situation has deteriorated once again in recent years, as the international community has shifted its focus to other global emergencies.
Experts say the most effective way to treat diarrhoea is through a combination of ORS and zinc tablets, which decrease the severity and duration of an attack.
Both treatments are cheap and simple to administer - but are not currently reaching millions of children in the developing world.
Access to clean water and good hygiene practices are extremely effective in preventing childhood diarrhoea.
Hand washing with soap has been shown to reduce rates by more than 40%.
It is estimated that 88% of diarrhoeal diseases worldwide are attributable to unsafe water, inadequate sanitation and poor hygiene.
As of 2006, an estimated 2.5bn people had no access to sanitary facilities, and nearly one in four people in developing countries was practicing open defecation.
Vaccination against rotavirus, which causes 40% of hospital admissions from diarrhoea in children under five worldwide, has recently been recommended for inclusion in all national immunisation programmes.
Experts say accelerating introduction of the vaccine in Africa and Asia - where the rotavirus has most impact - must be made a top priority.