What Does a Positive Fecal Occult Blood Test Mean?

Update Date: 2024-05-21 Source: Network

Fecal occult blood test is a chemical colorimetric method used to detect the presence of hemoglobin and other products in feces where bleeding cannot be confirmed by visual inspection or microscopy. When the fecal occult blood test is positive or "+" is displayed on the medical examination report, it indicates the occurrence of bleeding in the digestive tract with a blood loss of more than 5ml.

Here are some possible scenarios:

1. Upper Gastrointestinal Bleeding: When the bleeding occurs in the upper gastrointestinal tract with a blood loss of 5 to 10ml, the fecal occult blood test may be positive or intermittently positive. This could be due to bleeding from gastric and duodenal ulcers or esophageal variceal rupture, and further investigation is needed to determine the cause.

2. Digestive Tract Cancer: The positive rate of fecal occult blood test in patients with digestive tract cancer is 95%. However, a positive fecal occult blood test alone cannot confirm the diagnosis of digestive tract cancer. Further tests such as routine fecal examination, abdominal ultrasound, blood routine, and CRP are required, and these must be conducted under the guidance of a doctor.

3. Drug-induced Bleeding: Individuals with no history of gastrointestinal diseases or bleeding who take large doses of irritating drugs in a short period and subsequently have a positive fecal occult blood test may have drug-induced acute gastrointestinal mucosal bleeding.

4. Other Causes: Other conditions such as epidemic hemorrhagic fever, intestinal tuberculosis, ulcerative conjunctivitis, colonic polyps, and hookworm disease can also lead to a positive fecal occult blood test. Therefore, the fecal occult blood test can also be used to diagnose these conditions.