Which test detects occult blood in the stool?

• A. Pancreatitis
• B. Varices
• C. Small Bowel Obstruction- SBO
• D. Stool guaiac test

Answer: (C)

Occult blood in the stool means there’s hidden bleeding somewhere in the gastrointestinal tract. The test designed to detect this is the stool guaiac test. It uses guaiac-impregnated paper and relies on a peroxidase reaction from heme in blood. When blood is present, the reaction changes the paper color (usually turning it blue), signaling occult blood. This screening tool helps identify hidden GI bleeding from sources like ulcers or colorectal neoplasia before it’s visible. It’s important to know that results can be influenced by diet and medications, so proper collection and preparation are essential for accuracy. The other terms describe conditions rather than a testing method for occult blood; they may be related to GI bleeding in some cases, but they do not detect occult blood in stool.