Abstract
In the first place, 136 cases in whom colorectal adenoma and/or early cancer were detected using total colonoscopy or barium enema with subsequent total colonoscopy at the outpatient clinic were studied. Fifty point nine percent of the lesions were located proximal to the sigmoid-descending colon junction, whereas 27.2% of the cases (14.3% of the cases with lesions 6mm or more) had only lesions proximal to this junction. Approxi-mately half the cases had multiple lesions, which were mostly located on both sides of this junction. Therefore, the majority of cases with colorectal adenoma and/or early cancer, especially over 80% of cases with lesions 6mm or more, may be detected if screening sigmoidofiberscopy and subsequent total colonoscopy for cases with positive screening sigmoidofiberscopy are performed. Among 2, 170 cases screened with sigmoidofiberscopy at the physical checkup, 10 cases (0.46%), including 2 cases detected by subsequent total colonoscopy, had early cancers and 143 cases (6.6%) had adenomas. In screening for colorectal neoplasia, even cases without prior colorectal neoplasia should undergo the second sigmoidofiberscopy a year after the first sigmoidofiberscopy in order to detect the lesions which might be overlooked at the time of the first sigmoidofiberscopy. After that, sigmoidofiberscopy every two years and an annual fecal occult blood testing will be enough.
