Breath hydrogen in hyposucrasia.

A simple and reliable test for the diagnosis of hyposucrasia is required, since this may be an unsuspected cause of long-standing gastrointestinal disorder. Furthermore little has been done to define the epidemiology of this condition, possibly because of the limitations of multiple blood-sampling. Breath hydrogen (H2) production after lactose ingestion is a reliable test for hypolactasia, and has now been measured after sucrose ingestion in eleven patients with various gastrointestinal symptoms. Six who had normal sucrase activity on jejunal biopsy produced no H2 after taking 50 g of sucrose. No H2 was produced in three patients with borderline hyposucrasia, either after 50 g sucrose or when retested using 100 g sucrose (two patients). However, the two patients with low jejunal sucrase activity showed rises of breath H2, after only 25 g glucose. Breath H2 measurement is a simple, accurate, and non-invasive test for diagnosing gastrointestinal symptoms due to hyposucrasia.