Fecal Blood Test
|Why is this test done?||This test is done to help diagnose various digestive tract disorders. It is used to detect blood in the stools that is invisible to the eye.|
|How to prepare:||
|Associated Tests:||If the test is positive, other exams will be done to identify the source of the blood.|
A very small amount of blood can be found in normal stools. This blood is invisible to the eye. When the digestive tract's mucosa is damaged, the stools will contain larger than normal amounts of blood.
What does a positive result mean?
Blood in the stools can be caused by several digestive tract disorders, such as polyps, ulcers, varicose veins, intestinal inflammatory diseases, recent trauma or surgery, haemorrhoids and certain cancers.
Factors that can affect the result of the test
Several factors can influence the result of this test and cause a false-positive result, for example eating foods made with blood or red meat in the three days before the test. Recent dental surgery, taking the sample during menses, hemorrhoid, bleeding of the gums or extreme physical activity may also cause false-positive results. Certain drugs can also be blamed, they include:
- acetylsalicylic acid (Aspirin™)
- dexamethasone (Decadron™)
- indomethacine (Indocid™)
- phenylbutazone (Tandearil ™)
- prednisone (Deltasone™)
- iron supplements (Palafer ™)
Vitamin C can also cause a false-positive result because the test detects it as blood. Bleeding haemorrhoids can also cause a false-positive result.
What you need to know before the test
Before going for blood tests, a procedure or other exam, it is best to always bring a list of all the drugs you take (prescription, OTC and natural health products). Unless told otherwise, you should take your medication as usual on the day of the test. When in doubt, ask your pharmacist for more information.
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.