A positive test result indicates that abnormal bleeding is ocurring somewhere in the digestive tract.
1 As a result, a positive chemical fecal occult blood test can be caused by bleeding anywhere in the stomach or intestines, but a positive immunologic fecal occult blood test only occurs when there is bleeding into the colon. A chemical fecal occult blood test is inexpensive and easy, but it has several disadvantages. 1  Substances in fruits and vegetables can mimic heme and cause chemical fecal occult blood tests to be falsely positive, that is, falsely abnormal. The fecal occult blood test results are largely affected by how you prepare for the test, so it is important to follow the instructions carefully. Because certain foods can alter the test results, a special diet is often recommended for 48-72 hours before the test. The fecal occult blood test requires the collection of 3 small stool samples. Usually the samples are a bit of stool collected on the end of an applicator. The stool samples should be taken one day apart, because colon cancers may bleed from time to time, rather than consistently. Fecal Occult Blood Test (FOBT). The fecal occult blood test (FOBT) is a type of screening that could indicate colorectal cancer, but not diagnose it. This test checks for blood in the stool which cannot be seen with the naked eye. If blood is detected, additional testing would be required to determine the source of the blood. Fecal occult blood (FOB) refers to blood in the feces that is not visibly apparent (unlike other types of blood in stool such as melena or hematochezia). In the event of a positive fecal occult blood test, the next step in the workup is a form of visualization of the gastrointestinal tract by one of several means: 1  Sigmoidoscopy, an examination of the rectum and lower colon with a lighted instrument to look for abnormalities, such as polyps. The main use for the fecal occult blood test (FOBT) or the fecal immunochemical test (FIT) is as a screen for early colon cancer. Most cases of colon cancer begin with the development of benign intestinal polyps. Benign polyps are relatively common in people over the age of 50. For the guaiac-based FOBT, a positive test result indicates that abnormal bleeding is occurring somewhere in the digestive tract. This blood loss could be due to ulcers, diverticulosis, polyps, inflammatory bowel disease, hemorrhoids, blood swallowed due to bleeding gums or nosebleeds, or benign or cancerous tumors. 1 Positive result. 2  A fecal occult blood test is considered positive if blood is detected in your stool samples. 3  You may need additional testing — such as a colonoscopy — to locate the source of the bleeding. 1 If you had the test to screen for colon cancer and you're at average risk — you have no colon cancer risk factors other than age — your doctor may recommend waiting one year and then repeating the test. 2  Positive result. 3 (December 2008). Fecal occult blood (FOB) refers to blood in the feces that is not visibly apparent (unlike other types of blood in stool such as melena or hematochezia). A fecal occult blood test (FOBT) checks for hidden (occult) blood in the stool (feces). Newer tests look for globin, DNA, or other blood factors including transferrin, while conventional stool guaiac tests look for heme. In the event of a positive fecal occult blood test, the next step in the workup is a form of visualization of the gastrointestinal tract by one of several means: 1  Sigmoidoscopy, an examination of the rectum and lower colon with a lighted instrument to look for abnormalities, such as polyps. The fecal occult blood test (FOBT) is a lab test used to check stool samples for hidden (occult) blood. Occult blood in the stool may indicate colon cancer or polyps in the colon or rectum — though not all cancers or polyps bleed.  A fecal occult blood test checks a stool sample for blood that can't be seen with the naked eye. Blood in the stool is a sign of bleeding in the digestive tract. This could indicate cancer, polyps, hemorrhoids, diverticulosis, or inflammatory bowel disease, also called colitis.  Font Size. A. A. A. When doctors test for fecal occult blood they are testing for the presence of microscopic or invisible blood in the stool, or feces. Fecal occult blood can be a sign of a problem in your digestive system, such as a growth, or polyp, or cancer in the colon or rectum. 
http://www.medicinenet.com/fecal_occult_blood_tests/page2.htm http://www.webmd.com/digestive-disorders/digestive-diseases-stool-testing-blood-fecal-occult-blood-test http://stopcoloncancernow.com/colon-cancer-prevention/screening-methods/fecal-occult-blood-test-fobt https://en.wikipedia.org/wiki/Fecal_occult_blood https://labtestsonline.org/understanding/analytes/fecal-occult-blood/tab/test http://www.mayoclinic.org/tests-procedures/fecal-occult-blood-test/basics/results/PRC-20014429 https://en.wikipedia.org/wiki/Fecal_occult_blood http://www.mayoclinic.org/tests-procedures/fecal-occult-blood-test/basics/definition/prc-20014429 http://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=167&ContentID=fecal_occult_blood http://www.webmd.com/colorectal-cancer/guide/fecal-occult-blood-test
what is a Positive fecal occult blood test