[Hydrogen (H2) exhalation tests--methods for general practice].

According to the literature as well as to own experience hydrogen breath tests seem to be suitable for a gastroenterologist's practice because of their practicability (this means non invasive and cheap methods) and their diagnostic relevance (sensitivity, specificity). Although hydrogen breath test with lactose is now the best way for diagnosis of lactose intolerance, hydrogen breath test with glucose as a mean of investigation of small bowel bacterial overgrowth still is subject to discussion. Lactulose hydrogen breath test in order to estimate small bowel transit time is of minor importance in gastroenterologist's practice. Yet at special questions it still may be of relevance (e.g. suspicion of functional diarrhea).