Evaluation of the barium-enema examination and colonoscopy in diagnosis of colonic cancer.

The diagnostic value of colonoscopy was investigated in 123 patients with certain or questionable cancer of the colon as demonstrated by an ordinary barium-enema examination. The diagnosis was revised by laparotomy or clinical follow-up studies in cases of patients having no operation. The following conclusions were deduced: 1) The number of unnecessary laparotomies may be reduced by doing colonoscopy in patients with certain or questionable cancer of the colon as demonstrated by ordinary barium-enema studies. 2) The gain in diagnostic value of adding a colonoscopy to a barium-enema examination is more pronounced in patients with questionable than in those with certain cancer as visualized by the barium-enema studies. 3) The risk of missing a cancer of the colon during colonoscopy is very small if an experienced examiner looking for cancer performs the colonoscopy. 4) Colonoscopy is of little diagnostic value in cases of patients who have radiologic evidence of stenosis of the sigmoid colon. 5) The number of patients selected for colonoscopy on the basis of radiologic evidence suggesting cancer probably can be reduced by refinement of the barium-enema examination.