Fecal Occult Blood Testing
Which Test?
Soft Indications for FOBT Use?
October 2011
There are other potential or “soft” indications for use of fecal blood testing, but these are not supported by evidence and have not been addressed in formal guidelines. For example, what about the value of fecal blood testing in patients with dark stools? The most important action in such circumstances is to assess the hematologic and hemodynamic status and let these parameters direct management decisions. Guaiac testing can be misleading, as causes other than bleeding (such as iron ingestion) can lead to both black stools and positive guaiac reactions. Furthermore, reducing agents (like vitamin C) can cause false negatives in face of elevated blood levels. Fecal blood testing may be reasonable if the patient is stable and a lab-based test, such as HemoQuant, would be best choice. In those with GI symptoms, some have advocated that use of fecal blood testing will help identify those with organic etiologies. However, studies addressing this application have shown that the positive predictive value is minimally affected and this practice has generally not been advised.
Soft Indications for FOBT Use? |
Jump to section:
- Introduction
- Occult Gastrointestinal (GI) Bleeding: Definition
- Quantity of GI Bleeding Required to "See" Blood in Stool
- Fecal Occult Blood Tests
- Why Detect Occult GI Bleeding?
- Causes of Fe Deficiency in Industrialized Countries (Average %)
- Causes of Occult GI Bleeding
- Fecal Detection of Ingested Blood
- Iron Deficiency or Anemia: Which Test?
- CRC Screening: Target Lesions
- Occult Bleeding From Colorectal Cancer
- Fecal Blood Testing for Colorectal Cancer (CRC)
- FOBT Screening
- Stool Test Detection of CRN in Screen Setting
- Laboratory Testing vs Office Digital Rectal Exam (DRE)
- Evaluation of Fecal Immunochemical Testing (FIT) Assays
- FIT Specificity
- CRC Screening by FOBTs
- CRC Screening Guidelines*
- CRC Screening: Which Fecal Blood Test?
- Soft Indications for FOBT Use?
- Fecal Occult Blood Tests Summary
- Mayo Medical Laboratories Tests
- Questions?
- Disclosures
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