How you prepareBy Mayo Clinic staff
Various foods, dietary supplements and medications can affect the results of some fecal occult blood tests — either indicating that blood is present when it isn't (false-positive) or missing the presence of blood that's actually there (false-negative). To ensure accurate test results, follow your doctor's instructions carefully.
For about three days before the test, your doctor may ask you to avoid:
- Certain fruits and vegetables, including broccoli and turnips
- Red meat
- Vitamin C supplements
- Pain relievers, such as aspirin, ibuprofen (Advil, Motrin, others)
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