title: Prospective study of motor, sensory, psychologic, and autonomic functions in patients with irritable bowel syndrome.
abstract: OBJECTIVE
  The aim of this study was to assess pathophysiology in irritable bowel syndrome (IBS).
  
  
  METHODS
  A total of 122 IBS patients (3 male) and 41 healthy females underwent the following: questionnaires (symptoms, psychology), autonomic function, gut transit, gastric volumes, satiation, rectal compliance, and sensation (thresholds and pain ratings) testing. Proportions of patients with abnormal (<10th and >90th percentiles) motor or sensory functions according to bowel symptoms (constipation [C], diarrhea [D], mixed [M),) pain/bloat, and number of primary symptoms were estimated.
  
  
  RESULTS
  IBS subgroups (C, D, M) were similar in age, gastric and small-bowel transit, satiation, gastric volumes, rectal compliance, sensory thresholds, and pain ratings. IBS was associated with body mass index, somatic symptoms, and anxiety and depression scores. Significant associations were observed with colonic transit (IBS-C [P = .078] and IBS-D [P < .05] at 24 h; IBS-D [P < .01] and IBS-M [P = .056] at 48 h): 32% of IBS patients had abnormal colonic transit: 20.5% at 24 hours and 11.5% at 48 hours. Overall, 20.5% of IBS patients had increased sensation to distensions: hypersensitivity (<10th percentile thresholds) in 7.6%, and hyperalgesia (pain sensation ratings to distension >90th percentile for ratings in health) in 13%. Conversely, 16.5% of IBS patients had reduced rectal sensation. Pain greater than 6 times per year and bloating were not associated significantly with motor, satiation, or sensory functions. Endorsing 1 to 2 or 3 to 4 primary IBS symptoms were associated with abnormal transit and sensation in IBS.
  
  
  CONCLUSIONS
  In tertiary referral (predominantly female) patients with IBS, colonic transit (32%) is the most prevalent physiologic abnormality; 21% had increased and 17% had decreased rectal pain sensations. Comprehensive physiologic assessment may help optimize management in IBS.
authors.affiliation: Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), College of Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Camilleri
authors.forename: Sanna
authors.initials: S
authors.lastname: McKinzie
authors.forename: Irene
authors.initials: I
authors.lastname: Busciglio
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Low
authors.forename: Seth
authors.initials: S
authors.lastname: Sweetser
authors.forename: Duane
authors.initials: D
authors.lastname: Burton
authors.forename: Kari
authors.initials: K
authors.lastname: Baxter
authors.forename: Michael
authors.initials: M
authors.lastname: Ryks
authors.forename: Alan R
authors.initials: AR
authors.lastname: Zinsmeister
mesh_terms: D015746:Abdominal Pain; D000328:Adult; D005260:Female; D005772:Gastrointestinal Transit; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000503:physiopathology* / Q000523:psychology*; D008297:Male; D009043:Motor Activity; D011446:Prospective Studies; D012677:Sensation / Q000502:physiology; D011795:Surveys and Questionnaires