title: Symptomatic fructose malabsorption in irritable bowel syndrome: A prospective study.
abstract: BACKGROUND
  Fructose can trigger or worsen symptoms in irritable bowel syndrome (IBS) patients. The aim of this study was to determine the prevalence of symptomatic fructose malabsorption in IBS patients and to test whether the patient's characteristics can help to detect a fructose malabsorption.
  
  
  METHODS
  Ninety Rome III IBS patients (predominant diarrhoea (IBS-D): 31%, predominant constipation (IBS-C): 18%, mixed type (IBS-M): 51%) were included prospectively. After exclusion of a small intestinal bacterial overgrowth by a glucose breath test, fructose malabsorption was assessed by a five-hour breath test, with symptom monitoring, after a 25 g load of fructose. An increase of more than 20 ppm of hydrogen (H2) or methane (CH4) levels in the exhaled air led to the diagnosis of malabsorption.
  
  
  RESULTS
  Fructose test was abnormal in 20/90 patients among whom only 35% were intolerant, with a simultaneous rise of H2/CH4 levels and the onset of abdominal discomfort or diarrhoea. IBS characteristics were not predictive even if young (p = 0.031) and male IBS patients (p = 0.029) were at higher risk of malabsorption. At variance, 18 additional patients experienced intestinal symptoms during the test despite normal fructose absorption.
  
  
  CONCLUSIONS
  After a 25 g fructose load, symptomatic fructose malabsorption and intolerance without malabsorption were detected in 22% and 28% of IBS patients respectively.
authors.affiliation: Gastroenterology Department, Rouen University Hospital, Rouen, France ; INSERM UMR-1073, Rouen University Hospital, Rouen, France.
authors.forename: Chloé
authors.initials: C
authors.lastname: Melchior
authors.affiliation: INSERM UMR-1073, Rouen University Hospital, Rouen, France ; Physiology Department, Rouen University Hospital, Rouen, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Gourcerol
authors.affiliation: INSERM UMR-1073, Rouen University Hospital, Rouen, France ; Nutrition Unit, Rouen University Hospital, Rouen, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Déchelotte
authors.affiliation: INSERM UMR-1073, Rouen University Hospital, Rouen, France ; Physiology Department, Rouen University Hospital, Rouen, France.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Leroi
authors.affiliation: Gastroenterology Department, Rouen University Hospital, Rouen, France ; INSERM UMR-1073, Rouen University Hospital, Rouen, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ducrotté
keywords: FODMAPs; Fructose malabsorption; breath tests; irritable bowel syndrome