Comparison of predictive value for colorectal cancer in subjects with and without rectal bleeding

BACKGROUND/AIMS: To clarify the association between a sign of rectal bleedi ng and colorectal cancer, and to reveal the relationship of rectal bleeding to the results of an immunochemical fecal occult blood test. METHODOLOGY: In a population-based cross sectional study, 30,138 subjects w ho 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 wer e 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 pr edictive value was 6.4% and 3.3% in subjects with and without rectal bleedi ng, 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 betw een the subjects with rectal bleeding presentation and colorectal cancer, a nd a sign of rectal bleeding and the results of an immunochemical fecal occ ult blood test.