Gastrointestinal function in malnutrition

Diarrhoea of unknown cause is a common problem in malnutrition. Lactose malabsorption has been suggested as a contributing factor in some cases. An investigation of sugar absorption has therefore been made in 10 malnourished children shortly after admission, and again after clinical recovery. Four other recovered children were also studied. Sugar absorption was measured in a 40 cm. segment of the jujunum, which was perfused with solutions, of glucose, lactose and sucrose. During the perfusion of each solution, the mortality of the intestine was measured by the injection of a single dose of nonabsorbable dye into part of the test segment. The concentration and rate at which the dye passed the end of the test segment were used to calculate the mean transit time, flow rate and volume of fluid in a 25 cms. length of the segment. All malnourished children had a defect of glucose absorption, which improved after 6 to 16 weeks on a high protein diet. Lactose and sucrose absorption were defective in some of the malnourished children. The poor disaccharide absorption was associated with low disaccharide hydrolysis rates, which were related to low disaccharidase enzyme levels in the jejunal mucosa. Disaccharide hydrolysis and absorption improved after a high protein diet. Mortality studies demonstrated that the mean transit time was inversely proportional to the unabsorbed sugar in the test segment. Even at the low rate of perfusion made in these studies malnourished children appeared to have a less distensible intestinal wall (AU)