Checking for Fecal Occult Blood With Digital Rectal Examinations

To the Editor.—  In their recent article, Eisner and Lewis¹ attempt to answer a clinically important question, whether it is worthwhile to test stool obtained on routine rectal examination for occult blood. Unfortunately, the inclusion of an unspecified number of symptomatic and anemic subjects severely limits the usefulness and applicability of this study.A fecal occult blood test is superfluous in symptomatic or iron-deficient older adults. In these patients, colonoscopy or barium enema is almost always done regardless of a fecal occult blood test result because of its low sensitivity. Indeed, the fecal occult blood test will be negative up to 50% of the time in cases of proven colon carcinomas².The real question is whether doing occult blood testing on stool obtained during rectal examination is an effective screening tool in asymptomatic adults. I would be most interested to know how many of the 270 subjects included