title: Characterization of the alternating bowel habit subtype in patients with irritable bowel syndrome.
abstract: BACKGROUND
  Due to a wide range of symptom patterns, patients with irritable bowel syndrome (IBS) are often subgrouped by bowel habit. However, the IBS subgroup with alternating bowel habits (IBS-A) has been poorly characterized.
  
  
  OBJECTIVE
  (i) To determine a set of bowel habit symptom criteria, which most specifically identifies IBS patients with an alternating bowel habit, (ii) to describe IBS-A bowel symptom patterns, and (iii) to compare clinical characteristics among IBS-A, constipation-predominant (IBS-C), and diarrhea-predominant IBS (IBS-D).
  
  
  METHODS
  One thousand one hundred and two Rome I positive IBS patients were analyzed. Three sets of potential criteria for IBS-A were developed and compared by multirater Kappa test. Gastrointestinal, psychological, extraintestinal symptoms, and health-related quality of life were compared in IBS-A, IBS-C, and IBS-D using chi(2) test and analysis of variance (ANOVA).
  
  
  RESULTS
  Stool consistency was determined to be the most specific criteria for alternating bowel habits. IBS-A patients reported rapid fluctuations in bowel habits with short symptom flares and remissions. There was a greater prevalence of psychological and extraintestinal symptoms in the IBS-A subgroup compared to IBS-C and IBS-D. No differences were seen between bowel habit subtypes in health-related quality of life.
  
  
  CONCLUSIONS
  IBS-A patients have rapidly fluctuating symptoms and increased psychological comorbidity, which should be taken into account for clinical practice and clinical trials.
authors.affiliation: CNS/WH: Center for Neurovisceral Sciences & Women's Health, Department of Medicine, UCLA, and the VA Greater Los Angeles Healthcare System, Los Angeles, California, USA.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Tillisch
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Labus
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Naliboff
authors.forename: Roger
authors.initials: R
authors.lastname: Bolus
authors.forename: Michael
authors.initials: M
authors.lastname: Shetzline
authors.forename: Emeran A
authors.initials: EA
authors.lastname: Mayer
authors.forename: Lin
authors.initials: L
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000150:complications / Q000523:psychology; D015897:Comorbidity; D003248:Constipation / Q000209:etiology* / Q000523:psychology; D003863:Depression / Q000150:complications / Q000523:psychology; D003967:Diarrhea / Q000209:etiology* / Q000523:psychology; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000145:classification / Q000175:diagnosis* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D011788:Quality of Life / Q000523:psychology; D012189:Retrospective Studies; D013001:Somatoform Disorders / Q000150:complications / Q000523:psychology