Fecal occult blood test
Fecal occult blood is detected through microscopic analysis or chemical tests for hemoglobin (blood) in the stool. This test finds blood in the stoll that is typically unseen without analysis. People with blood in their stool may have a cancerous growth which indicates the presence of colorectal cancer. The test requires collection of three stool samples that are examined microscopically for blood.
It is important to understand that when blood is present in a stool sample, it can be due to other noncancerous factors, such as certain medications or foods, gastrointestinal bleeding, or hemorrhoids. Testing is recommended starting at age 50 by many organizations including the American Cancer Society.