False-positive fecal occult blood results can be caused by ingestion of:

Question

Quizplus · Accepted Answer

Several interfering substances may give false-positive results for occult blood.These include those of dietary origin with peroxidase activity,especially myoglobin and hemoglobin in red meat.Vegetable peroxidase,as found in horseradish,can also cause false-positive results.Several foods have been identified as causing erroneous reactions.These include turnips,broccoli,bananas,black grapes,pears,plums,and melons.Cooking generally destroys these peroxidases,and therefore patients are generally instructed to eat only cooked foods.

False-Positive Fecal Occult Blood Results Can Be Caused by Ingestion