Taking science where the diarrhoea is.

With attack rates exceeding two episodes per year in the young diarrhoea with attendant dehydration is by far the major single killer in the developing world. An invariable accompaniment of the more insidious and chronic protein-energy malnutrition (PEM), diarrhoea is itself an acute form of malnutrition: fluid-electrolyte malnutrition (FEM). Scientific attention to FEM has focused heavily on mechanisms of pathogenesis and disordered physiology, often to the neglect of preventive and effective control measures. A notable exception was the huge step from the short-circuit chamber to the cholera ward which carried the science of coupled transport to the field. Glucose-electrolyte solutions provide effective prevention and treatment of dehydration and, where combined with early proper feeding, an interruption of the FEM-PEM cycle. Wider use of this simple technology awaits greater understanding and interact-on with the social systems that determine the ecology of diarrhoeal disease.