Question

A specimen is tested for occult blood and found to be positive. A brief history on the patient revealed that he had recently eaten a meal that included steak with horseradish dressing. What is the most appropriate course of action?

Answer 1

Ans) The nurse should instruct the patient to avoid red meat, chicken, fish, horseradish, and certain raw fruits and vegetables for 3 days prior to fecal occult blood testing.

- As for false-positive test results, a variety of drugs and foods can cause a positive reaction in the absence of colorectal neoplasia, including drugs that cause gastro-intestinal bleeding (among which nonsteroidal anti-
inflammatory drugs are the most widely used) and foods, such as red meat, horseraddish and some vegetables, that contain large amounts of hemoglobin or peroxidase.

- It makes sense, on the face of it, to attempt to eliminate these causes of false-positive results by providing dietary instructions at the time of testing.

- After all, positive results, even one trace positive result in six specimens, should be followed with colonoscopy—even if occult
bleeding might be attributed to another cause.

- Screening is like looking for a needle in a haystack; therefore, physicians cannot afford to disregard any clue to the presence of cancer.