title: Intestinal gas in plain abdominal radiographs does not correlate with symptoms after lactulose challenge.
abstract: METHODS
  Intestinal gas production and abdominal discomfort can be triggered by the ingestion of carbohydrates such as lactulose. Using plain abdominal radiographs, we studied whether subjective complaints after a lactulose breath test would be quantitatively related to intestinal gas volumes.
  
  
  METHODS
  Abdominal symptoms after the breath test were quantified by a written questionnaire and gas volumes were scored in plain abdominal radiographs, in 50 consecutive patients with unexplained, irritable bowel syndrome-like symptoms. Breath excretion of hydrogen and methane was determined in all patients.
  
  
  RESULTS
  Forty-two (84%) of the patients claimed that their post-breath test symptoms were a true replicate of their customary discomfort. Total symptom scores (sum of scores for pain/discomfort, borborygmi, bloating, diarrhea, constipation) or any specific symptom score were not significantly correlated to gas volume scores (r=-0.04; P=0.8 for total symptom score). The 13 (26%) methane producers had significantly higher mean gas volume scores compared with nonproducers (0.38 vs. 0.24; P=0.0008), but fewer symptoms (total symptom score 11.9 vs. 18.2; P=0.17).
  
  
  CONCLUSIONS
  Intestinal gas volume, as scored in plain abdominal radiographs, is not correlated with abdominal discomfort after lactulose challenge. Intestinal gas may not be the major cause of abdominal discomfort following carbohydrate ingestion in patients with functional gut disorders.
authors.affiliation: Department of Clinical Nutrition, Haukeland University Hospital, Bergen, Norway. mette.morken@helse-bergen.no
authors.forename: Mette Helvik
authors.initials: MH
authors.lastname: Morken
authors.forename: Audun Elnaes
authors.initials: AE
authors.lastname: Berstad
authors.forename: Gunnar
authors.initials: G
authors.lastname: Nysaeter
authors.forename: Arnold
authors.initials: A
authors.lastname: Berstad
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001944:Breath Tests / Q000379:methods; D005260:Female; D005285:Fermentation; D005414:Flatulence / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D005740:Gases / Q000032:analysis*; D006801:Humans; D006859:Hydrogen / Q000378:metabolism; D007422:Intestines / Q000000981:diagnostic imaging / Q000503:physiopathology; D043183:Irritable Bowel Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007792:Lactulose; D008297:Male; D008697:Methane / Q000096:biosynthesis; D008875:Middle Aged; D011859:Radiography; D012720:Severity of Illness Index
chemical_list: D005740:Gases; D007792:Lactulose; D006859:Hydrogen; D008697:Methane