Response of severe infantile diarrhoea to soya-based feeds

Ongoing acute diarrhoea in infancy may respond to a change from a cows' milk to a soya-based formula. This is usually ascribed to the change in carbohydrate content of the feed but the ideal carbohydrate composition of the soya feed is uncertain. Twenty infants with severe watery diarrhoea persisting 2 days after initial rehydration and refeeding with a cows' milk formula were randomly allocated to one of two soya-based formulas. In one the carbohydrate was a mixture of sucrose and glucose polymers and in the other all the carbohydrate glucose polymers. No advantage was noted for either formula. Approximately 50% of each group responded to dietary change. The prompt cessation of diarrhoea and the disappearance of evidence of carbohydrate malabsorption suggests the response is due to the removal of lactose from the diet. Those infants that did not respond had evidence of continuing carbohydrate malabsorption and were not simply lactose-intolerant. The pathogenesis of this carbohydrate malabsorption and the possible relationship to small-bowel bacterial overgrowth requires further investigation.