The recent article by Barr et al, "Mucosal Function and Breath Hydrogen Excretion: Comparative Studies in the Clinical Evaluation of Children with Nonspecific Abdominal Complaints" (Pediatrics 68:526, 1981), provided some useful data on the utility of the lactose breath hydrogen test (LBHT) for the diagnosis of lactase deficiency in children with nonspecific abdominal complaints. However, two comments are in order.
1. Because new diagnostic tests must be compared to a "gold standard" test for evaluative purposes, the meat of this article resides in table 3, in which a LBHT is compared with lactase activity demonstrated on biopsy material.