What percentage of colonic cancers is out of reach of the flexible sigmoidoscope?
Over the past 4 decades, the distribution of colon cancers has shifted toward the right colon. About 40% to 50% of colonic cancers are out of reach of the flexible sigmoidoscope.
This is why screening for colonic carcinoma requires a total colonic examination, either by colonoscopy or by double-contrast barium enema examination.
