We thank Professors Johann and Heinz Hammer for their interest in our recent publication, as well as their comments.1 The article examined potential associations between the symptoms provoked (intolerance) and the gases produced owing to incomplete absorption after fructose or lactose ingestion in patients with functional gastrointestinal disorders (FGID). The associations were assessed in a large number of patients to gain an improved understanding of the pathophysiologic mechanisms in FGID, rather than to address the breath test techniques themselves.