title: Association between irritable bowel syndrome and colorectal cancer: a nationwide population-based study.
abstract: OBJECTIVE
  To determine whether irritable bowel syndrome (IBS) is associated with an increased risk for the subsequent colorectal cancer (CRC).
  
  
  METHODS
  We identified 91,746 patients who were diagnosed with IBS between 2000 and 2010 from the Taiwan National Health Insurance Research Database (NHIRD) as the study cohort, and randomly extracted the data of 183,492 patients matched by sex, age, and baseline year for the comparison cohort. The follow-up period was terminated after CRC development, withdrawal from the national health insurance (NHI) system, or at the end of 2010. Cumulative incidences and hazard ratios (HRs) of CRC development were determined.
  
  
  RESULTS
  During the first 2years of follow-up, the subsequent CRC incidence rates in the IBS and comparison cohorts were 37.3 and 5.61 per 10,000person-years, respectively (adjusted HR, 6.72; 95% CI, 5.70-7.92; p<.0001). Thereafter, the risk did not differ significantly between the 2 cohorts (adjusted HR, 1.08; 95% CI, 0.93-1.26); the participants in the IBS cohort commonly underwent more colonoscopies/sigmoidoscopies than did the non-IBS cohort.
  
  
  CONCLUSIONS
  IBS was not associated with the long-term development of CRC in Taiwan. The increased risk of CRC in the first 2years may have occurred because some CRC patients were initially misclassified as IBS patients.
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Cheng-Wen
authors.initials: CW
authors.lastname: Hsiao
authors.affiliation: Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wen-Yen
authors.initials: WY
authors.lastname: Huang
authors.affiliation: Division of Colorectal Surgery, Department of Surgery, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Tao-Wei
authors.initials: TW
authors.lastname: Ke
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chih-Hsin
authors.initials: CH
authors.lastname: Muo
authors.affiliation: Division of Colorectal Surgery, Department of Surgery, China Medical University Hospital, Taichung, Taiwan.
authors.forename: William Tzu-Liang
authors.initials: WT
authors.lastname: Chen
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan; Department of Public Health, China Medical University and Hospital, Taichung, Taiwan.
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.affiliation: Graduate Institute of Clinical Medicine Science and School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan. Electronic address: d10040@mail.cmuh.org.tw.
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003113:Colonoscopy / Q000706:statistics & numerical data; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D016208:Databases, Factual; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006949:Hyperlipidemias / Q000453:epidemiology; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D043183:Irritable Bowel Syndrome / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
keywords: Cohort study; Colorectal cancer; Irritable bowel syndrome