Investigation of reserve functional ability of small intestine by xylose test after food loading.

D-xylose test in control group and in subjects with proximal chronic enteritis and colitis was carried out in three modifications: after fasting according to conventional method, after preliminary meat loading, and also after glucose loading. Meat caused considerable rise of xylose absorption that was much greater in control group than in subjects with chronic enteritis. In subjects with chronic enteritis the deviation from the norm after meat loading was observed more often than in the conventional test. Glucose reduced D-xylose absorption. In moderate enteritis the reduction was less obvious than in the control group. Double xylose test after meat and glucose loading is recommended as a method of functional investigation of small intestine.