title: Comparison of predictive value for colorectal cancer in subjects with and without rectal bleeding.
abstract: OBJECTIVE
  To clarify the association between a sign of rectal bleeding and colorectal cancer, and to reveal the relationship of rectal bleeding to the results of an immunochemical fecal occult blood test.
  
  
  METHODS
  In a population-based cross sectional study, 30,138 subjects who received immunochemical fecal occult blood screening with a 2-day method were divided into two groups, according to the results of a questionnaire on a sign of rectal bleeding, and the positivity rate of an immunochemical occult blood test as well as the predictive value for colorectal cancer were compared in the two groups.
  
  
  RESULTS
  The fecal occult blood test was positive in 8.8% of subjects with rectal bleeding and in 6.0% of subjects without rectal bleeding, and the predictive value was 6.4% and 3.3% in subjects with and without rectal bleeding, respectively, showing a significant difference in the positivity rate (p<0.001) as well as the predictive value (p<0.05) between these two groups.
  
  
  CONCLUSIONS
  These findings indicate that there are positive relations between the subjects with rectal bleeding presentation and colorectal cancer, and a sign of rectal bleeding and the results of an immunochemical fecal occult blood test.
authors.affiliation: Department of Public Health, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakama
authors.forename: T
authors.initials: T
authors.lastname: Kayano
authors.forename: T
authors.initials: T
authors.lastname: Katsuura
authors.forename: T
authors.initials: T
authors.lastname: Kamigaito
authors.forename: S
authors.initials: S
authors.lastname: Shimada
authors.forename: N
authors.initials: N
authors.lastname: Nishikawa
authors.forename: S
authors.initials: S
authors.lastname: Yoshii
authors.forename: N
authors.initials: N
authors.lastname: Kamijo
mesh_terms: D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D003430:Cross-Sectional Studies; D006471:Gastrointestinal Hemorrhage / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008403:Mass Screening; D009780:Occult Blood; D011237:Predictive Value of Tests