Disordered small intestinal motility: a rational basis for toddlers' diarrhoea.

Toddler diarrhoea is the commonest cause of chronic diarrhoea without failure to thrive in childhood, but its pathogenesis remains obscure. We have studied upper small intestinal motility in three groups of children (control group 1 - children with no intestinal pathology undergoing duodenal intubation, n = 6; control group 2 - children with gastrointestinal pathology other than toddler diarrhoea, n = 11; control group 3 - children with toddler diarrhoea, n = 8). We studied fasting motor patterns and the response of the migrating motor complex to intravenous cholecystokinin and an intraduodenal bolus of 5% dextrose. The characteristics of the migrating motor complex in the three groups did not differ but their response to dextrose did. Intraduodenal dextrose disrupted the migrating motor complex in four out of four children in group 1; seven out of nine children in group 2; and nil of eight children with toddler diarrhoea in group 3. We suggest that this failure of intestinal motor response may play a major role in the pathogenesis of the diarrhoea in this condition.