Hydrogen breath test in patients with severe constipation: the interference of the mixing of intestinal content. Issue 12 (December 2014)

• Record Type: Journal Article
• Authors: Di Stefano, M.; Mengoli, C.; Bergonzi, M.; Miceli, E.; Pagani, E.; Corazza, G. R.
• Is Part Of: Neurogastroenterology & motility. Volume 26:Issue 12(2014:Dec.)
• Page Start: 1754
• Page End: 1760
• Publication Date: 2014-12
• Subjects: Gastrointestinal system -- Motility -- Periodicals; Gastrointestinal system -- Innervation -- Periodicals; 616.33
• DOI: 10.1111/nmo.12456
• Languages: English
• ISSNs: 1350-1925

Abstract

<abstract abstract-type="main" id="nmo12456-abs-0001"> <title>Abstract</title> <sec id="nmo12456-sec-0001" sec-type="section"> <title>Background</title> <p>The diagnostic accuracy of the hydrogen (H<sub>2</sub>) breath test might be reduced by the release of preformed H<sub>2</sub>, trapped in hard stools. Test solution ingestion might induce the mixing of colonic content and a false positive result. We studied severely constipated patients, at diagnosis and after the normalization of bowel function, to clarify whether this mechanism affects test results.</p> </sec> <sec id="nmo12456-sec-0002" sec-type="section"> <title>Methods</title> <p>Twenty functional constipated patients, 10 consecutive patients with functional diarrhea and 10 healthy volunteers underwent (i) a H<sub>2</sub> breath test after lactulose, to exclude differences among the groups in fermenting capacity; (ii) breath H<sub>2</sub> excretion monitoring after non‐absorbable, non‐fermentable PEG‐electrolyte solution, to exclude the role of the delivery to the colon of preexisting fermentable substrates or of the release of preformed H<sub>2</sub> entrapped in the feces; (iii) H<sub>2</sub> measurement during a 7‐h fasting period, to exclude the role of spontaneous variations of breath gas excretion; and (iv) breath H<sub>2</sub> excretion monitoring after PEG, after normalization of bowel function.</p> </sec> <sec id="nmo12456-sec-0003" sec-type="section"> <title>Key Results</title> <p>All the subjects excreted similar amounts of H<sub>2</sub> after lactulose. After PEG, only severely constipated patients showed significant breath H<sub>2</sub> excretion, theoretically able to induce a false positivity of the lactose breath test in 70% of patients and a false positivity of glucose breath tests in 50% of patients. Breath H<sub>2</sub> excretion after PEG disappeared if fecal consistency improved after therapy.</p> </sec> <sec id="nmo12456-sec-0004" sec-type="section"> <title>Conclusions & Inferences</title> <p>Severely constipated patients may harbor preformed gas in hard stools which can be released when mixing of the intestinal content is induced. This mechanism may interfere with breath test results.</p> </sec> </abstract>