Nearly two million children die of diarrhoea each year, even though treating the ailment is relatively simple and "almost miraculous", the World Health Organization said on Tuesday.
Research into childhood diarrhoea has declined since the 1980s, keeping pace with dwindling funds for a disease that nonetheless accounts for 20 percent of all child deaths, the WHO said in a statement.
"Funds available for research into diarrhoea are much lower than those devoted to other diseases that cause comparatively few deaths," it said.
The most immediate challenge is to ensure all children suffering from diarrhoea can access a simple, 25-year-old treatment consisting of zinc tablets and a mixture known as Oral Rehydration Salts or ORS, said Dr. Olivier Fontaine, a WHO medical officer specialising in child health.
The WHO estimates some 50 million children have been saved thanks to the mixture, which costs only 30 US cents (25 euro cents) per child.
"ORS is essentially a pinch of salt and a handful of sugar mixed with clean water," Fontaine said.
"Having seen, first hand, the devastation that childhood diarrhoea can cause and also the almost miraculous, life-saving power of ORS and zinc, I certainly hope that we'll receive the support we need to come up with answers to some of the key questions that remain," he said.
The international Red Cross also warned Tuesday that diarrhoeal diseases, such as cholera, are on the rise and increasingly a major cause of diseases and deaths throughout the world.
The International Red Cross and Red Crescent Societies noted that in 2007 and 2008, some 60 percent of requests by Red Cross societies for emergency relief funds were related to outbreaks of diarrhoeal diseases.
"This is about 35 percent more compared to similar statistics in 2006," it added.
Uli Jaspers, head of the IFRC water and sanitation team, said: "We have noticed a significant increase in the number of operations undertaken to respond to acute situations, especially in sub-Saharan Africa, most recently in Zimbabwe."
The cholera epidemic in Zimbabwe has claimed more than 4,000 lives and more than 89,000 people have the disease, the World Health Organization said in a new toll published Monday.