The diagnostic value of the D-xylose absorption test in adult coeliac disease.

The 25-g D-xylose absorption test was assessed in a total of 40 adult patients with coeliac disease before and after treatment and in 25 control patients. Because of a large overlap neither the urinary excretion rates nor the 1-h blood concentrations were of any use in the assessment of the individual patients. The overlap was most pronounced for the urine values. In contrast to an earlier report, we could not demonstrate an increased discrimination when the blood concentrations were corrected to a constant body surface area. The D-xylose absorption test provides very little guidance in determining the effect of dietary treatment in coeliac disease. Our results emphasize the serious limitations of the test, and we recommend that it be abandoned.