Contribution of the gastrointestinal tract below the stomach to the 13C-urea breath test.
BACKGROUND
Graham et al. [Lancet, I (1987) 1174] found a late increase of 13C enrichment in the 13C-urea breath test 120 min after administration of labeled urea to patients without Helicobacter pylori infection. This may give false positive results.


OBJECTIVE
We designed this study to elucidate the contribution of the gastrointestinal tract below the stomach to the 13C-urea breath test.


METHODS
Twenty-eight patients with dyspeptic symptoms who gave their consent were enrolled.


METHODS
Patients underwent the 13C-urea breath tests both via the mouth (as usual) and the duodenum (labeled urea introduced to the second portion). Breath samples were collected at baseline, 5, 15, 30, 45, 60, 90, 120, 150 and 180 min for analysis. H. pylori status was defined by the CLOtest and by histological examination.


RESULTS
There was no late increase in 13C enrichment of 13C-urea breath test for eight H. pylori negative patients either via the mouth or the duodenum. For those H. pylori positive patients, seventeen had no late rise 13C enrichment of the 13C-urea breath test via the duodenum and three patients had a rise after 15 min.


CONCLUSIONS
No late rise in 13CO2 excretion to cause a positive 13C-urea breath test up to 180 min after the administration of labeled urea was found in the present study.
Department of Internal Medicine, Far Eastern Memorial Hospital, 21, Nan-Ya S. Road, Sec. 2, Pan-Chiao City, Taipei County, 220 Taiwan. thlee@ha.mc.ntu.edu.tw
T H
TH
Lee
J C
JC
Yang
S C
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Lee
S S
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Farn
T H
TH
Wang
D000328:Adult; D000368:Aged; D001944:Breath Tests; D002247:Carbon Isotopes; D002404:Catheterization; D004386:Duodenum; D016145:Endoscopy, Digestive System; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000302:isolation & purification; D006801:Humans; D041741:Lower Gastrointestinal Tract / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D014508:Urea; D014510:Urease / Q000032:analysis
D002247:Carbon Isotopes; D014508:Urea; D014510:Urease