title: [An epidemiologic study of irritable bowel syndrome in Beijing - a stratified randomized study by clustering sampling].
abstract: OBJECTIVE
  To explore the prevalence of irritable bowel syndrome (IBS) and its risk factors in Beijing.
  
  
  METHODS
  Phase I: a screening program for IBS was carried out in Beijing area according to symptoms using both Manning (modified including constipation) and Rome criteria. Random clustered sampling involving 2 486 subjects of the inhabitants was carried out under stratification of city, suburban and rural areas. Sample size of each studied area was in proportion to the population of the area. The range of age was 18 - 70. All subjects studied were requested to fill in a questionnaire assisted by trained doctors or medical students during the visit to their families. Phase II: a small number of patients who fulfilled the Manning criteria were further selected to undergo detail clinical examination in the hospital including laboratory examination, abdominal ultrasonography, colonoscopy or/and barium enema to exclude organic disease of the colon. Prevalence of IBS of the population was then adjusted by the rate of correct diagnosis during phase II study. Minnesota Multi - Personality Indices was used in some cases. Potential risk factors were explored by comparing frequencies among IBS group and non - IBS group using chi(2) and logistic analysis of multifactors.
  
  
  RESULTS
  The adjusted point prevalence of IBS in Beijing according to Manning criteria was 7.26%, in contrast to Rome criteria - 0.82%. Higher prevalence rate of IBS in the city (10.50%) than in rural areas (6.14%) (P < 0.001) was noticed. Male to female ratio was 1:1.15 with majority of IBS fell in age 18 - 40 (51.6%), and among intellectuals. Our study indicated that history of dysentery (OR = 3.00), exposure to coldness (OR = 1.55), ingestion of cold food and raw materials (OR = 1.24) might serve as the most important risk factors (P < 0.001). Patients with IBS seemed to have a higher tendency of abnormal personalities.
  
  
  CONCLUSIONS
  IBS is a common disorder in Beijing which deserves greater care.
authors.affiliation: Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
authors.forename: G
authors.initials: G
authors.lastname: Pan
authors.forename: S
authors.initials: S
authors.lastname: Lu
authors.forename: M
authors.initials: M
authors.lastname: Ke
authors.forename: S
authors.initials: S
authors.lastname: Han
authors.forename: H
authors.initials: H
authors.lastname: Guo
authors.forename: X
authors.initials: X
authors.lastname: Fang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000453:epidemiology* / Q000209:etiology; D016015:Logistic Models; D008950:MMPI; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D012307:Risk Factors; D012494:Sampling Studies; D011795:Surveys and Questionnaires