Detection of primary and secondary sucrose malabsorption in children by means of the breath hydrogen technique.

Eighty-one breath hydrogen tests were performed in 72 children who were investigated either because of chronic diarrhoea or recurrent abdominal pain, or because they were relatives of patients with congenital sucrase-isomaltase deficiency. The results of tests on 16 patients were positive (sucrase-isomaltase deficiency, seven patients; secondary sucrose malabsorption, nine patients). Hydrogen production was higher in patients with sucrase-isomaltase deficiency (mean, 96 ppm; range, 20 ppm to 432ppm) than in those with secondary sucrose malabsorption (mean, 21 ppm; range, 12ppm to 51ppm). All patients with positive test results responded to sucrose restriction, and those with secondary malabsorption subsequently became well. The breath hydrogen test is a sensitive, non-invasive method for detecting sucrose malabsorption, whether due to a primary deficiency or secondary to other bowel disorders. Guidelines for improving the accuracy and reproducibility of the breath hydrogen test are discussed.