Will I need to do anything to prepare for the test?Certain foods and drugs may affect the results of a guaiac smear method (gFOBT) test. Your health care provider may ask you to avoid the following:Nonsteroidal, anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen, or aspirin for seven days prior to your test. If you take aspirin for heart problems, talk to your health care provider before stopping your medicine. Acetaminophen may be safe to use during this time, but check with your health care provider before taking it.More than 250 mg of vitamin C daily from supplements, fruit juices, or fruit for seven days prior to your test. Vitamin C can affect the chemicals in the test and cause a negative result even if there is blood present.Red meat, such as beef, lamb, and pork, for three days prior to the test. Traces of blood in these meats may cause a false-positive result.There are no special preparations or dietary restrictions for a fecal immunochemical test (FIT).
