title: Comparison of the prevalence of fructose and lactose malabsorption across chronic intestinal disorders.
abstract: BACKGROUND
  Fructose malabsorption, lactose malabsorption and an early rise in breath hydrogen after lactulose (ERBHAL) may play roles in induction of symptoms in gastrointestinal conditions.
  
  
  OBJECTIVE
  To compare prevalence and interactions of fructose malabsorption, lactose malabsorption and ERBHAL among healthy subjects and those with chronic intestinal disorders using consistent breath hydrogen testing methodologies.
  
  
  METHODS
  Consecutive series of Caucasian patients with Crohn's disease (n = 91), ulcerative colitis (56), functional gastrointestinal disorders (FGID) (201), coeliac disease (136) and 71 healthy volunteers underwent breath hydrogen testing using lactulose, fructose and lactose.
  
  
  RESULTS
  Early rise in breath hydrogen after lactulose occurred more commonly in healthy controls (39%) than in Crohn's disease (20%) and untreated coeliac disease (14%; P < 0.008), but not FGID (27%), ulcerative colitis (26%) or treated coeliac disease (29%). Fructose malabsorption was more frequent in Crohn's disease (61%) than other groups (33-44%, P < 0.05). Lactose malabsorption was most common in Crohn's disease (42%) and ulcerative colitis (40%) and uncommon (10%) in 79 patients with newly diagnosed coeliac disease. In Crohn's disease, concurrent Fructose malabsorption and lactose malabsorption was most common (29%), and the association of fructose malabsorption with ERBHAL seen overall (62%) was not observed (36%, P < 0.0001).
  
  
  CONCLUSIONS
  Carbohydrate malabsorption and ERBHAL are normal physiological phenomena. The abnormal patterns observed in Crohn's disease may have pathogenic importance.
authors.affiliation: Department of Medicine, Monash University and Box Hill Hospital, Level 8 Clive Ward Centre, 16 Arnold Street, Box Hill, Vic. 3128, Australia. jacqueline.barrett@med.monash.edu.au
authors.forename: J S
authors.initials: JS
authors.lastname: Barrett
authors.forename: P M
authors.initials: PM
authors.lastname: Irving
authors.forename: S J
authors.initials: SJ
authors.lastname: Shepherd
authors.forename: J G
authors.initials: JG
authors.lastname: Muir
authors.forename: P R
authors.initials: PR
authors.lastname: Gibson
mesh_terms: D000328:Adult; D000367:Age Factors; D001944:Breath Tests / Q000379:methods; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D005632:Fructose / Q000009:adverse effects*; D006801:Humans; D006859:Hydrogen; D015212:Inflammatory Bowel Diseases / Q000150:complications*; D007787:Lactose Intolerance / Q000150:complications* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012737:Sex Factors
chemical_list: D005632:Fructose; D006859:Hydrogen