Optimal Dietary Conditions for Hemoccult Testing

Abstract

Preliminary rehydration of Hemoccult II slides increases slide sensitivity for blood and lowers the false-negative rate for colorectal cancer. To test the effect of this modification on the false-positive rate due to peroxidase-containing foods, 156 healthy young subjects crossed between diets of differing peroxidase content. Hemoccult II slides were prepared in duplicate for testing with and without rehydration. When developed without rehydration, only seven (0.4%) of 1856 slides were positive, the positive results occurring with challenge diets containing 250 g rare red meat. With preliminary rehydration, 53 (5.7%) of 926 slides were positive, in 26 (17%) of the 156 subjects on a challenge..