title: Irritable bowel syndrome and bronchial hyperresponsiveness: is there a link?
abstract: OBJECTIVE
  Many studies have demonstrated a high prevalence of bronchial hyperresponsiveness in patients with irritable bowel syndrome (IBS). The aim of this 24-month prospective study was to evaluate the prevalence of IBS in asthmatic patients.
  
  
  METHODS
  We analyzed 623 asthmatic patients that were evaluated for body mass index, sex, and age before undergoing both a methacholine challenge test (MCHt) and skin prick tests.
  
  
  RESULTS
  We found that 276 asthmatic patients (44.3%) were positive on the MCHt, while 347 (55.7%) were negative. We also found that 27 (9.7%) of the 276 patients with a positive MCHt and 44 (12.7%) of the 347 patients with a negative MCHt were affected by IBS. Therefore, there was no statistically significant difference between positive MCHt tests and IBS. The PC(20) (mean provocation concentration of methacholine producing a 20% reduction in forced expiratory volume in 1 s < or =16 mg/ml) in all patients tested was 8.64 +/- 2.58 mg/ml, being 8.75 +/- 2.52 and 8.55 +/- 2.32 mg/ml for males and females, respectively.
  
  
  CONCLUSIONS
  These results do not demonstrate a relationship between MCHt and IBS. However, a relationship might still exist in a subpopulation of patients whose symptoms worsen by stress.
authors.affiliation: Division of Human Nutrition, Department of Biomedical Sciences, University G. D'Annunzio, Chieti, Italy. griccioni@hotmail.com
authors.forename: G
authors.initials: G
authors.lastname: Riccioni
authors.forename: R
authors.initials: R
authors.lastname: Della Vecchia
authors.forename: V
authors.initials: V
authors.lastname: Menna
authors.forename: T
authors.initials: T
authors.lastname: Staniscia
authors.forename: C
authors.initials: C
authors.lastname: Di Ilio
authors.forename: P
authors.initials: P
authors.lastname: Conti
authors.forename: N
authors.initials: N
authors.lastname: D'Orazio
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000150:complications* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000453:epidemiology*; D008297:Male; D016210:Methacholine Chloride; D015995:Prevalence; D011446:Prospective Studies; D013315:Stress, Psychological
chemical_list: D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride