title: Impact of orocecal transit time on patient´s perception of lactose intolerance.
abstract: BACKGROUND
  symptoms attributed to the lactose intolerance are an important public health issue because of their prevalence and social relevance. Also because they may cause undue rejection of dairy products consume with potential health consequences. Transit time is a putative factor implied in the severity of symptoms associated with lactose.
  
  
  OBJECTIVE
  to elucidate the relation between orocecal transit time (OCTT) and lactose intolerance symptoms.
  
  
  METHODS
  observational study in patients referred to a lactose hydrogen breath test who showed an increase in breath H2 excretion higher than 25 ppm. OCTT was measured with the breath test and symptoms of lactose tolerance with a validated scale. Symptoms were measured twice: before receiving the lactose, inquiring about self perceived symptoms when patients consumed dairy products at home ("home symptoms"), and again after completing the lactose breath test ("test symptoms").
  
  
  RESULTS
  161 patients were included. There was no correlation between OCTT and home symptoms (r = -0.1). When OCTT was faster than 60 minutes, intensity of "test symptoms" was similar to "home symptoms". However, in patients with normal or slow OCTT, the "home symptoms" were more intense than the "test symptoms" (p < 0.05). At home, symptoms were independent of OCTT but with the lactose test load the symptoms were proportionately more intense with faster OCTT.
  
  
  CONCLUSIONS
  in lactose maldigesters, selfreported symptoms of lactose intolerance are more pronounced at home than after a high lactose challenge. Intolerance symptoms that patients attributed to lactose consume at home are due to factors other than fast OCTT.
authors.forename: Francesc
authors.initials: F
authors.lastname: Casellas
authors.forename: Anna
authors.initials: A
authors.lastname: Aparici
authors.forename: Maite
authors.initials: M
authors.lastname: Casaus
authors.forename: Purificación
authors.initials: P
authors.lastname: Rodríguez
authors.forename: Juan R
authors.initials: JR
authors.lastname: Malagelada
mesh_terms: D000328:Adult; D001944:Breath Tests; D002432:Cecum; D059026:Diagnostic Self Evaluation; D005260:Female; D005772:Gastrointestinal Transit / Q000502:physiology*; D006801:Humans; D007787:Lactose Intolerance / Q000175:diagnosis* / Q000503:physiopathology*; D008297:Male; D009055:Mouth; D011795:Surveys and Questionnaires; D013997:Time Factors