The World Health Organization [link] has produced figures showing that
2.2 million children will die from diarrhoea and related diseases this year; 80% of them in the first two years of their life. Or if you prefer, think of these figures in another way
42,000 a week,
6,000 a day,
four every minute,
one every fourteen seconds.
Diarrhoea in the developed world is, generally, not life threatening; it is simply unpleasant. Both the deaths and the "unpleasentness" can be cured by drinking the following mixture:

1 x litre of cold water
1 x teaspoon of salt
8 x teaspoons of sugar