title: Clinical patterns over time in irritable bowel syndrome: symptom instability and severity variability.
abstract: OBJECTIVE
  The clinical course of irritable bowel syndrome (IBS) remains poorly known. In 209 IBS patients meeting Rome II criteria (137 females and 72 males) we evaluated: (1). changes in frequency and intensity of abdominal pain/discomfort, abnormal number of bowel movements, loose or watery stools, defecatory urgency, hard or lumpy stools, straining during bowel movements, and feeling of incomplete evacuation); (2). use of resources, HRQoL, and psychological well being.
  
  
  METHODS
  Observational, prospective, multicenter study. Symptoms were registered in a diary over two 28-day periods with an interval of 4 wk; direct resource use and indirect costs were noted weekly. Three HRQoL questionnaires were administered.
  
  
  RESULTS
  High-intensity symptoms were present on more than 50% of the days. Sixty-one percent were classified in the same IBS subtype on both occasions (kappa= 0.48), while 49% had the same symptom predominance and intensity (kappa= 0.40). The greatest instability was observed among diarrhea (D-IBS) and constipation (C-IBS) subtypes: only 46% and 51% remained in the same pattern with a tendency to shift to alternating diarrhea/constipation subtype (A-IBS); however, practically no patient changed from D-IBS to C-IBS, or vice versa. The most reliable symptom characteristic was frequency, followed by intensity and number of episodes. Symptom frequency and intensity were directly related to resource use and HRQoL impairment.
  
  
  CONCLUSIONS
  IBS symptoms are instable over time and variables in intensity. Many patients with D-IBS or C-IBS move to A-IBS; however, shift from D-IBS to C-IBS, or vice versa, is very infrequent.
authors.affiliation: Institute of Functional and Motor Digestive Disorders, Centro Médico Teknon, Barcelona, Spain.
authors.forename: Fermin
authors.initials: F
authors.lastname: Mearin
authors.forename: Eva
authors.initials: E
authors.lastname: Baró
authors.forename: Montse
authors.initials: M
authors.lastname: Roset
authors.forename: Xavier
authors.initials: X
authors.lastname: Badía
authors.forename: Natalia
authors.initials: N
authors.lastname: Zárate
authors.forename: Isabel
authors.initials: I
authors.lastname: Pérez
mesh_terms: D015746:Abdominal Pain / Q000209:etiology; D003248:Constipation / Q000209:etiology; D003967:Diarrhea / Q000209:etiology; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000145:classification / Q000150:complications / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D012959:Socioeconomic Factors