Lethal familial protracted diarrhoea.

24 children with severe protracted diarrhoea from 10 families, in which at least one sibling was affected, are reported. In two families the siblings were from 1st-cousin marriages, in one family both parents had unaffected children from previous marriages, and in another family the mother had a normal daughter from an earlier marriage. The onset of the diarrhoea was on the first day of life in 12 infants, some time during the first 17 days in 10, and at 13 weeks and 1 year 6 days in the remaining two. In each case the diarrhoea was 'cholera-like'. Investigations failed to show any of the established causes of protracted diarrhoea and 21 (87 5 %) infants died after an illness that had lasted between 12 days and 6 years 38 weeks, despite periods of prolonged intravenous feeding and the administration of a wide variety of pharmacological agents. The 2 patients who recovered appeared to do so spontaneously. 14 (58 %) had associated extra-gastrointestinal or gastrointestinal-related anomalies. Steady-state perfusion studies were performed in the proximal jejunum of 2 patients, and in the colon of one. In both cases the jejunum was in a net secretory state with respect to water, glucose absorption was markedly reduced, and the transmural potential difference was also depressed; in one of these patients fructose absorption was also reduced, and in the other colonic function appeared to be normal. These studies suggest that the diarrhoea resulted from small intestinal secretion overwhelming the reabsorptive capacity of a normally-functioning colon. Although this series of lethal protracted diarrhoea does not represent