Hemoglobin in stool (qualitative, occult)
This test checks for hidden (occult) blood in your stool, which may indicate bleeding from the digestive tract. It’s often used as part of screening for conditions like colorectal cancer or gastrointestinal ulcers.
["A positive result may signal an underlying digestive issue requiring further evaluation."]
Key facts at a glance
- LOINC
- 48047-5
- Short code
- Hgb Vom gastro Ql
- Synonyms
- Hgb Vom gastro Ql
- Category
- hematology
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- 7 N/A – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Doctors may recommend this test if you have symptoms like unexplained weight loss, persistent abdominal pain, black or bloody stools, or if you’re at higher risk for digestive cancers. It can also be part of routine screening for older adults or those with a family history of colorectal issues.
How Is the Test Performed?
A small sample of your stool is collected in a special container, often during a bowel movement. The sample is then tested in a lab using chemical methods to detect hidden blood. No special preparation is needed, but you may be advised to avoid certain foods or medications that could interfere with results.
What Do the Results Mean?
A positive result means hidden blood is present, which could signal conditions like bleeding from the esophagus, stomach, intestines, or rectum. A negative result means no visible blood was detected in this sample, but further testing may still be needed if symptoms persist.
What Are Possible Causes?
Occult blood in stool can result from conditions such as hemorrhoids, polyps, inflammatory bowel disease, or cancers of the digestive tract. It can also occur from minor injuries or medications.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Occult blood in stool (qualitative)
Frequently asked questions
What does a positive occult blood test mean?
Can diet affect this test?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy