• Three widely used screening tests for enteropathy in childhood are the lactose breath hydrogen test, the one-hour serum d-xylose absorption test, and the 72-hour fecal fat determination. To our knowledge, no study has compared these three tests and jejunal biopsy results. A retrospective survey of all jejunal biopsy results at Children's Hospital, Boston, from July 1983 to July 1984 was undertaken to evaluate which test best predicted a normal biopsy result. None of the screening tests was ideal. The lactose breath test had low sensitivity and specificity and did not correlate significantly with biopsy results. The d-xylose and fecal fat tests were each significantly correlated with biopsy results; a normal result of either test was highly predictive of a normal biopsy result. Combining the results of two or more screening tests did not improve predictive value. The xylose test is preferable on the basis of greater sensitivity and ease of patient compliance.