What is a Fecal Occult Blood Test (FOBT)?

If you are not familiar with this test, here are some of the basics.


A doctor may perform a FOBT to test for a variety of intestinal conditions marked by blood in the stool. While perhaps the most well known condition which causes blood to be seen in a stool sample is colorectal cancer, it is far from the only reason this may occur. When blood is present in stool, it most frequently reveals that there is blood loss in the gastrointestinal tract. A doctor takes a small sample of stool and tests it by placing it on a chemically treated material, typically a card or a cloth, and if the material turns blue then blood is present.

If the doctor does find blood, it may be due to any one of the following conditions. While these are the most common, there may still be other reasons for blood loss.


If you have hemorrhoids, chances are you may realize this before you ever receive any test results. Many people are extremely uncomfortable from these swollen veins in or around the anus. They typically cause itching and burning but can be treated to help the veins return to normal size.


Peptic Ulcer
This ulcer is located in the gastrointestinal tract and is very acidic which is typically why it is painful. They are most frequently found in the duodenum rather than the stomach. The most common symptom is rectal bleeding, which occurs as the ulcer begins eroding a blood vessel.


Angiodysplasia of the Colon
Angiodysplasia of the colon is a condition resulting in multiple lesions often categorized by acute blood loss. Some possible treatments include endoscopic treatment and in severe cases of blood loss, a blood transfusion may be necessary.


Most easily recognized by an unnatural yellowing of the skin, jaundice is responsible for disruptions in the makeup of the blood. It is often tested for with a FOBT.

Anal Fissures

These small tears in the anal tissue lining may result in blood loss.


Colorectal Cancer
This type of cancer affects the large intestines and often the only symptom of colorectal cancer is the appearance of blood in the stool.


Crohn’s Disease
This disease results in digestive upset and blood in the stool due to the presence of ulcers and inflammation of the lining in the digestive system.


If you have a history of any of these conditions or would like to be tested, speak to you physician or ask your pharmacist for an at-home version of the FOBT.


Leave a Reply