Abstract
Four hundred and sixty eight cases of colorectal cancer were operated in the past ten years in our Institute. A preoperative colonoscopy was performed for two hundred and eighty two of them. The indications and associated problems of colonoscopy for colorectal cancer were studied. The insertion rate of the colonoscope up to the cancer was high in the left colon, it was, however, low in the right colon. Therefore total colonoscopy was said to be not necessarily the best way for a screening method of colorectal cancer. The indications of colonoscopy were for the following cases; 1) Equivocal barium enema. 2) Cases in which rectal bleeding persists in spite of nomal barium enema. Moreover, it was found that the colonoscopy up to the splenic flexure was important to detect colorectal cancer as screening for the patients over forty years old having bloody stool. Right colon cancers were often too advanced at the time of the examination. Hence it was deduced that the low insertion rate of the colonoscope for it was derived from abdominal dissemination, poor movability of adjacent loop due to invasion of the cancer and adhesion between abdominal wall and cancer. Barium enema should be performed to these cases of unsuccessfull colonoscopy as stated above, or to the cases whose bleeding sources were not specified.
