Chronic diarrhoeas in infancy and childhood: I: The D-xylose tolerance test

Abstract

The D-xylose absorption tolerance test was carried out by the oral administration of 15 g. D-xylose per m.2 body surface to 90 infants and children, 22 controls and 68 with chronic diarrhoeas. The evaluation of the test was based on the maximal concentration obtained in the blood (after one, two and three hours) and on the urinary excretion during the first 24 hours expressed as a percentage of the ingested amount. The former constituted a better means of discrimination between normal and pathological values. In the control group the mean values and the upper and lower limits (mean ± 2 standard deviations) were 48 (26-70) mg./100 ml. blood and 31 (16-59) % urinary excretion. In 10 patients with coeliac disease nine blood values and six urinary values were below the lower normal limit. In 25 patients with idiopathic diarrhoeas blood and urinary values were below the lower normal limit in seven and six cases respectively. For both groups the mean values were significantly lower than the control mean. This may suggest that the pathogenesis of idiopathic diarrhoeas is an absorption defect in the small intestine.