Stool Occult Blood

Stool Occult Blood

What it is

The Stool Occult Blood test detects hidden (occult) blood in a stool sample that is not visible to the naked eye. Occult blood in stool may indicate bleeding in the gastrointestinal (GI) tract, which can result from ulcers, polyps, cancers, or other digestive conditions. This test is commonly used as a screening tool for colorectal cancer and other GI disorders.

Uses

This test is used to:

• Screen for colorectal cancer or precancerous polyps.
• Detect hidden bleeding from ulcers, gastritis, or hemorrhoids.
• Evaluate causes of unexplained anemia (low red blood cell count).
• Monitor patients with known gastrointestinal conditions for bleeding.
• Guide further diagnostic testing, such as colonoscopy or endoscopy.

Symptoms / Conditions That May Lead to the Test

Doctors may recommend this test if you have:

• Unexplained fatigue, weakness, or anemia.
• Persistent changes in bowel habits (diarrhea, constipation).
• Abdominal pain, bloating, or discomfort.
• Blood seen in stool or black, tarry stools (melena).
• Family history of colorectal cancer or gastrointestinal bleeding disorders.
• Unexplained weight loss or loss of appetite.

Abnormal Results

• Positive Occult Blood: Indicates hidden bleeding in the GI tract. Possible causes include colorectal cancer, polyps, ulcers, diverticulosis, inflammatory bowel disease (IBD), or hemorrhoids. Further diagnostic tests are usually required.
• Negative Occult Blood: Suggests no hidden bleeding in the sample tested. However, intermittent bleeding may not always be detected, so repeated testing may be recommended in high-risk individuals.

Results are usually interpreted with medical history, physical examination, and additional imaging or endoscopy when necessary.

Risks

The test itself is non-invasive and safe. Risks are minimal but may include:

• False-positive results due to certain foods (e.g., red meat, raw vegetables) or medications (NSAIDs, aspirin).
• False-negative results if bleeding is intermittent or sample collection is incomplete.