Abstract
During the 5-year period 1973--77 there was a considerable change in infant feeding practice (the use of low solute cows' milk formulae instead of high solute formulae and the later introduction of solid foods into the diet) which should have led to a reduced incidence of hypernatraemia among infants admitted to hospital with gastroenteritis. We have compared the incidence of hypernatraemia in such infants admitted during three 12-month periods between January 1973 and December 1977. Our results show there was such a reduction; they also show that hypernatraemia did not occur in infants fed a low solute milk formula alone.