The urinary excretion of polyethylene glycol as a test for mucosal integrity in children with celiac disease: comparison with other noninvasive tests.

We compared the results of various noninvasive tests with small bowel histology in 61 children with celiac disease. The most sensitive predictors of small bowel histology were serum levels of anti-gliadin antibodies (AGAs) (90%) and the urinary excretion of polyethylene glycol (PEG) (69%). The sensitivity for the fecal fat analysis was 61% and for the D-xylose test 34%. The specificity was 96% for both the PEG and the D-xylose tests, 92% for the fecal fat, and 68% for AGAs. The predictive value of the PEG test was significantly better than that of D-xylose (p less than 0.05). The best combination of tests for the prediction of small bowel histology was the PEG test and the measurement of serum levels of AGAs. Agreement in the results of these two tests helps to time appropriately the second and third small bowel biopsies.