Fecal Occult Blood Test

A fecal occult blood test is a screening that looks for hidden (occult) blood in stool (poop). The test can identify tiny traces of blood that you can’t see on your own. It helps healthcare providers diagnose several health conditions.
What does a fecal occult blood test show?

Blood in the stool means there’s bleeding happening somewhere in your digestive tract. This type of bleeding isn’t normal and is usually a sign of a health condition, such as:

  • Anemia, when your body doesn’t have enough healthy red blood cells.
  • Colitis, inflammation or irritation in your colon.
  • Colorectal cancer, cancer that occurs in the lower part of your colon or rectum.
  • Diverticulosis, an expanded, bubble-like area on your colon wall.
  • Hemorrhoids, swollen veins inside your rectum or outside your anus.
  • Colon polyps, a flat, raised or stalk-like growth on your colon or rectal lining.
  • Ulcers, sores that develop in the digestive tract or rectum.
 

What is the purpose of a fecal occult blood test?

If you have certain symptoms, such as abdominal pain, fatigue, pain around your rectum or rectal bleeding, your healthcare provider may recommend a fecal occult blood test. The most common reason for an FOBT is to screen for colorectal cancer.

On its own, a fecal occult blood test can’t diagnose colorectal cancer or any digestive issue. Depending on the results of your FOBT, you may need more testing to confirm a diagnosis.