title: Self-reported dietary fructose intolerance in irritable bowel syndrome: Proposed diagnostic criteria.
abstract: OBJECTIVE
  To study the criteria for self-reported dietary fructose intolerance (DFI) and to evaluate subjective global assessment (SGA) as outcome measure.
  
  
  METHODS
  Irritable bowel syndrome (IBS) patients were randomized in an open study design with a 2 wk run-in on a habitual IBS diet, followed by 12 wk with/without additional fructose-reduced diet (FRD). Daily registrations of stool frequency and consistency, and symptoms on a visual analog scale (VAS) were performed during the first 4 wk. SGA was used for weekly registrations during the whole study period. Provocation with high-fructose diet was done at the end of the registration period. Fructose breath tests (FBTs) were performed. A total of 182 subjects performed the study according to the protocol (88 FRD, 94 controls).
  
  
  RESULTS
  We propose a new clinically feasible diagnostic standard for self-reported fructose intolerance. The instrument is based on VAS registrations of symptom relief on FRD combined with symptom aggravation upon provocation with fructose-rich diet. Using these criteria 43 of 77 patients (56%) in the present cohort of IBS patients had self-reported DFI. To improve the concept for clinical evaluation, we translated the SGA scale instrument to Norwegian and validated it in the context of the IBS diet regimen. The validation procedures showed a sensitivity, specificity and κ value for SGA detecting the self-reported DFI group by FRD response within the IBS patients of 0.79, 0.75 and 0.53, respectively. Addition of the provocation test yielded values of 0.84, 0.76 and 0.61, respectively. The corresponding validation results for FBT were 0.57, 0.34 and -0.13, respectively.
  
  
  CONCLUSIONS
  FRD improves symptoms in a subgroup of IBS patients. A diet trial followed by a provocation test evaluated by SGA can identify most responders to FRD.
authors.affiliation: Leif Kyrre Berg, Erik Fagerli, Department of Medicine, Hospital of Helgeland, 8613 Nordland, Norway.
authors.forename: Leif Kyrre
authors.initials: LK
authors.lastname: Berg
authors.affiliation: Leif Kyrre Berg, Erik Fagerli, Department of Medicine, Hospital of Helgeland, 8613 Nordland, Norway.
authors.forename: Erik
authors.initials: E
authors.lastname: Fagerli
authors.affiliation: Leif Kyrre Berg, Erik Fagerli, Department of Medicine, Hospital of Helgeland, 8613 Nordland, Norway.
authors.forename: Arnt-Otto
authors.initials: AO
authors.lastname: Myhre
authors.affiliation: Leif Kyrre Berg, Erik Fagerli, Department of Medicine, Hospital of Helgeland, 8613 Nordland, Norway.
authors.forename: Jon
authors.initials: J
authors.lastname: Florholmen
authors.affiliation: Leif Kyrre Berg, Erik Fagerli, Department of Medicine, Hospital of Helgeland, 8613 Nordland, Norway.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Goll
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001944:Breath Tests; D050528:Diet, Carbohydrate-Restricted; D005240:Feasibility Studies; D005260:Female; D005633:Fructose Intolerance / Q000175:diagnosis* / Q000178:diet therapy / Q000453:epidemiology; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000175:diagnosis* / Q000178:diet therapy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011237:Predictive Value of Tests; D015995:Prevalence; D015203:Reproducibility of Results; D057566:Self Report; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: Breath test; Dietary restriction; Fructose malabsorption; Functional bowel disease; Sugar intolerance