Fecal Occult Blood Test

Gastrointestinal bleeding can mean a lot of things, with colon cancer being the worst case scenario. Patients who would want to rule out if they have early onset of colon cancer or none may visit their physician and undergo fecal occult blood test.

A closer look at the fecal occult blood test

Fetal occult blood test is performed on stool samples of an individual suspected to have gastrointestinal disorders. Sometimes, the amount of blood in the stool is too small to be seen by the naked eye. This particular test will allow the physicians to see if there is indeed presence of blood in the stool.

When you talk of fecal occult blood, this is usually the end result of an internal bleeding that started from either the upper or lower gastrointestinal tract. Since the amount of blood is really few, testing will help in determining whether the patient has colon cancer or none.

Many medical organizations will usually advise people who are aged 50 and above to have themselves checked and opt for fecal occult blood test.

The process involved in fecal occult blood test

In doing the fecal occult blood test, the doctor will usually require you to have at least three samples of your stool for multiple testing. The reason for that is of course, they would want to provide you with the most accurate results possible.

Fecal occult blood test can be done through:

  1. Immunologic testing – In this type of testing, the stool sample is mixed with a solution containing globin. This substance is what makes up the protein content of the molecule of hemoglobin. A small amount of gold is also added because once the solution settles, a positive visible line will reflect in the test strip indicating the presence of blood in the sample.
  2. Chemical testing – In chemical testing, on the other hand, the solution that will be used for the sample contains an oxidizing chemical and guaiac. The blood will be seen if the solution turns blue when mixed in with the stool sample.

Between the two types, chemical testing is least expensive although it is inferior to immunologic testing since the latter is more sensitive and specific when it comes to determining the presence of blood in the stool sample. It is also more accurate in giving the results. With that, less follow-up examinations and tests will be required by the physician.

Preparing for the test

Patients who need to undergo the test need to follow the advice of their doctor when it comes to specific foods that should be avoided prior to the testing. The patient should do this few days before the test. But if the immunologic testing will be performed, then there will be less or no dietary restrictions at all.

Reading the results

Once the test results are with the doctor, he/she will disclose the information to the patient. If the test is negative, then there is nothing to worry about. However, a positive test result will mean that the patient has some type of abnormal bleeding happening somewhere in the gastrointestinal tract. The bleeding can actually mean anything from inflammatory bowel disease, ulcers, hemorrhoids, polyps, or cancerous tumors. The fecal occult blood test remains to be the most efficient way to detect early signs of colon cancer. The doctor may prescribe that you take the test again on another day to double-check and re-assess.

It is important that the patient should be reminded that a positive test does not necessarily mean colon cancer. Undergoing through other tests is highly recommended.


  • Fecal Occult Blood Test: WebMD