Occult Blood - Stool

Occult blood in stool means small amounts of blood not visible to the eye but detected by stool tests. It indicates bleeding somewhere in the gastrointestinal tract and can result from hemorrhoids, ulcers, polyps, inflammatory bowel disease, medications (like NSAIDs), or colorectal cancer. A positive result warrants further evaluation—often repeat testing and investigation with colonoscopy or other imaging to find and treat the source.

A positive stool occult blood test does not diagnose cancer but indicates gastrointestinal bleeding. Your doctor will review symptoms, medications, and likely recommend colonoscopy to find the source, plus blood tests (CBC, iron) and stool tests. Causes include hemorrhoids, ulcers, inflammatory bowel disease, or colorectal cancer. Seek prompt medical evaluation—urgent assessment is needed for anemia, ongoing bleeding, unexplained weight loss, or severe pain.

Only a small proportion of positive occult blood stool tests represent cancer—generally about 2–10%. Most positive results come from noncancerous causes (hemorrhoids, ulcers, polyps, medications, dietary factors). A positive test needs follow-up, usually colonoscopy, to confirm or exclude colorectal cancer; a negative test doesn’t completely rule it out.

Blood in a child’s stool is not common and should be evaluated. Small amounts often come from benign causes such as anal fissures from constipation or mild infections; persistent, large, or recurrent bleeding—or bleeding with fever, severe abdominal pain, weight loss, or pallor—may signal more serious conditions. Seek prompt medical review; urgent care or emergency evaluation is needed for heavy bleeding or signs of shock.

Occult blood — hidden blood in stool — ranges from minor causes (hemorrhoids, anal fissures, gastritis) to serious conditions (peptic ulcers, inflammatory bowel disease, colorectal polyps or cancer). It warrants medical evaluation because it can signal early cancer even without visible bleeding. Doctors typically repeat tests, check blood counts and iron, adjust medications, and often recommend colonoscopy, especially with anemia, weight loss, or persistent symptoms.

Seek urgent care if you pass large amounts of blood, have black/tarry stools, fainting, dizziness, low blood pressure, or heavy ongoing bleeding. See your doctor promptly if you notice persistent or recurrent bleeding, bright red blood with severe pain, unexplained weight loss, a change in bowel habits for more than two weeks, iron-deficiency symptoms, or if you’re over 50 or have a family history of colorectal cancer.