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Hydrogen breath test in patients with severe constipation: the interference of the mixing of intestinal content
Author(s) -
Di Stefano M.,
Mengoli C.,
Bergonzi M.,
Miceli E.,
Pagani E.,
Corazza G. R.
Publication year - 2014
Publication title -
neurogastroenterology and motility
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.489
H-Index - 105
eISSN - 1365-2982
pISSN - 1350-1925
DOI - 10.1111/nmo.12456
Subject(s) - lactulose , breath test , excretion , gastroenterology , medicine , ingestion , laxative , hydrogen breath test , peg ratio , constipation , lactose , chemistry , biochemistry , finance , economics , helicobacter pylori
Background The diagnostic accuracy of the hydrogen ( H 2 ) breath test might be reduced by the release of preformed H 2 , 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. Methods Twenty functional constipated patients, 10 consecutive patients with functional diarrhea and 10 healthy volunteers underwent (i) a H 2 breath test after lactulose, to exclude differences among the groups in fermenting capacity; (ii) breath H 2 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 2 entrapped in the feces; (iii) H 2 measurement during a 7‐h fasting period, to exclude the role of spontaneous variations of breath gas excretion; and (iv) breath H 2 excretion monitoring after PEG , after normalization of bowel function. Key Results All the subjects excreted similar amounts of H 2 after lactulose. After PEG , only severely constipated patients showed significant breath H 2 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 2 excretion after PEG disappeared if fecal consistency improved after therapy. Conclusions & Inferences 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.