The Oral D-Xylose Test in Healthy Infants and Children

THE ORAL D-xylose test, based upon the determination of 5-hour urinary recovery of D-xylose ( hereinafter referred to as xylose) after a loading dose of the pentose, has been widely employed in adults as a test of absorption. Since xylose is a simple sugar, digestion is unnecessary and absorption is independent of bile, intestinal, or pancreatic secretions. Xylose is absorbed chiefly in the duodenum and proximal jejunum. The primary use of this test, therefore, is in the demonstration of malabsorption states arising from lesions involving the upper small bowel wall such as gluten-induced enteropathy. This test is simple, reproducible, inexpensive, and valuable in the investigation of malabsorption states in adults.1-3In infants and children the performance of this test presents certain practical difficulties: (1) prolonged fasting with resultant dehydration in young infants, (2) the necessity for meticulous urine collection with its difficulties in young children; and (3) the necessity, on