<prompt> Positive D-xylose test indicates all of the following except: March 2011Pancreatic insufficiencySmall intestinal mucosal diseaseImpaired carbohydrate absorption in small intestineMalabsorption  <response>: Ans. A: Pancreatic insufficiency The urinary D-xylose test for carbohydrate absorption provides an assessment of proximal small-intestinal mucosal function Xylose: It is used to test for malabsorption by administration in water to the patient after fasting. If xylose is detected in blood andor urine within the next few hours, it has been absorbed by the intestines. Reduction of xylose by catalytic hydrogenation produces the non-cariogenic sugar substitute xylitol. D-xylose absorption test for mucosal disease or bacterial over growth, is normal in pancreatic insufficiency. 