What is Fecal Occult Blood Testing (FOBT)
 • Screening ...

What is Fecal Occult Blood Testing (FOBT)

 • Screening for colorectal cancer in average risk population in the ambulatory setting

    - Guaiac based (g-FOBT) or immunochemical test (FIT) 

    - g-FOBT is the older of the two and no longer recommended as first line screening

 • Recommended screening use:

    - Three separate stool samples. with applicator used to smear on card, NOT FROM DRE

 • gFOBT often misused (particularly on inpatient setting) for indications other than CRC screening (100% of time)

Why FOBT is NOT appropriate for GIB/anemia evaluation

 • False Positives

    - Ingested blood: epistaxis, gingival bleeding. pharyngitis

    - Mucosal inflammation: esophagitis, gastritis, IBD, cirrhosis

    - Medications: NSAlDs. iron supplementation, ASA, coumadin, antiplatelets, anticoagulants

    - Diet: red meat, broccoli, cauliflower, ETOH

 • False Negatives:

    - Ingestion of antioxidants (VitC)

    - Denatured from upper GIB

 • Does not change management and can lead to unnecessary testing, extended LOS

- University of Massachusetts GI Fellowship @UMassGI

#Fecal #OccultBlood #Testing #FOBT #Guaiac #FalsePositives #FalseNegatives #TWDFNR
Contributed by

Dr. Gerald Diaz
Board Certified Internal Medicine Hospitalist, GrepMed Editor in Chief 🇵🇭 🇺🇸 - Sign up for an account to like, bookmark and upload images to contribute to our community platform. Follow us on IG:  https://www.instagram.com/grepmed/ | Twitter: https://twitter.com/grepmeded/
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