Abstract
Over the past 20 years there have been many important advances in knowledge about diarrhoeal diseases of children. Of these, the development of oral rehydration therapy (ORT), has been outstanding. This is based on the observation that intestinal sodium transport is enhanced by glucose transport in the small intestine and that this sodium-coupled mechanism for glucose and water transport remains intact in the enterotoxigenic diarrhoeas despite the net secretory effects of bacterial enterotoxins on the small intestinal epithelium. The World Health Organisation has adopted ORT and strongly promoted its application for treatment of diarrhoeal diseases, particularly in developing countries. This has resulted in a drop in diarrhoeal disease mortality and the application of this treatment has been described in an Editorial in the Lancet as "potentially the most important medical advance this century".