title: Absence of gaseous symptoms during ingestion of commercial fibre preparations.
abstract: BACKGROUND
  While fibre is believed to cause gaseous symptoms, a study in healthy volunteers showed no increase in flatulence when the diet was supplemented with fermentable (psyllium) or non-fermentable (methylcellulose) fibre. However, extrapolation of this observation to subjects who use fibre is arguable since these individuals may have a propensity to gaseousness. In the present study, gaseous complaints during fibre ingestion were assessed in subjects who believed that a previous exposure to fibre induced gas.
  
  
  METHODS
  In a double-blind protocol, subjects were randomized to one of four treatment periods, during which the regular diet was supplemented for 1-week periods with two daily doses of: placebo 10 g, psyllium 3.4 g, methylcellulose 2 g or lactulose 5 g. A symptom diary was maintained for 1-week periods on or off treatment.
  
  
  RESULTS
  During treatment, the lactulose group passed gas significantly more often than did the psyllium or the methylcellulose group (P = 0.01). No other symptom was significantly different among the treatment groups.
  
  
  CONCLUSIONS
  (1) psyllium and methylcellulose did not cause greater gaseous symptomatology than did placebo in subjects who believed that these preparations caused gas; and (2) subjects commonly misidentify dietary components that cause gaseous symptoms.
authors.affiliation: The Minneapolis Veterans Affairs Medical Center, MN 55417, USA.
authors.forename: L
authors.initials: L
authors.lastname: Zumarraga
authors.forename: M D
authors.initials: MD
authors.lastname: Levitt
authors.forename: F
authors.initials: F
authors.lastname: Suarez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002400:Cathartics / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005414:Flatulence; D006801:Humans; D008297:Male; D008747:Methylcellulose / Q000627:therapeutic use*; D008875:Middle Aged; D011620:Psyllium / Q000627:therapeutic use*
chemical_list: D002400:Cathartics; D011620:Psyllium; D008747:Methylcellulose