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qFIT Testing for occult blood in stool

 

qFIT should now be performed in rectal bleeding – it is a measure of ‘colonic health’ and if negative suggests bleeding is from the anal verge.


Please note a qFIT is best taken from the centre of the stool and not following DRE.

  

In primary care, we can use qFIT with reasonable confidence:

  • For symptomatic patients who might have a colorectal malignancy, qFIT performs better than PSA for prostate cancer, CA125 for ovarian cancer and CXR for lung cancer
     
  • It also substantially reduces the number of colonoscopies performed
     
  • Of those with red flag symptoms suggesting colorectal cancer tested with qFIT, 99.4-100% will be detected, and less than 1% will test negative even though they had cancer (false negatives)
    • The risk of false negative seems to be more common in patients with IDA and beta-thalassemia trait, so a concurrent FBC can be useful
       
  • As it is not a perfect test, we need to safety-net and share uncertainty with our patients.

 

Risk of colorectal cancer (CRC):

  • In an asymptomatic patient >50yr old, the risk of CRC is about 1 in 200
     
  • In a symptomatic patient group, without qFIT testing, the risk of CRC is 3.3%
     
  • Using qFIT as a test in symptomatic patients defines 2 groups:
    • qFIT positive, with a risk of CRC of 16%
    • qFIT negative group (without IDA or a mass), with a risk that is below the asymptomatic population i.e. <1 in 200

 

When to use qFIT testing in primary care

qFIT testing to assess for the following symptoms on the Fast Track Colorectal Cancer pathway in adults at any age with:

  • Unexplained weight loss and abdominal pain
     
  • Change in bowels for >3 weeks
     
  • Abdominal pain
     
  • Weight loss
     
  • Unexplained rectal bleeding
     
  • Unexplained anaemia (with or without iron deficiency)
     
  • Any other GP concern

 

With the above criteria:

  • If qFIT positive (qFIT 10 or more), patients can be referred on the Fast Track colorectal referral formand will be seen within the usual fast track times
     
  • If qFIT negative (qFIT less than 10), patients can still be referred on the Fast Track colorectal form, but will be clinically assessed and subsequent tests under the colorectal cancer team will be booked to take place within 6-8 weeks.


Patients with the following can be referred on Fast Track without the qFIT result, however the qFIT result helps with subsequent test decisions:

  • Rectal mass
     
  • Abdominal mass
     
  • Unexplained anal mass or anal ulceration

    Nb. Please consider anal fissure prior to referral
  • Referred following investigation that suggests or confirms colorectal cancer


 Please see Iron Deficiency Anaemia guideline

 

Please note:

Although qFIT tests are reported as positive or negative, it’s important to note that it is a quantitative test.

With this in mind, the cut-off used by the lab varies depending on whether it is being done as a screening test or to test a symptomatic patient:

  • When FIT is used for symptomatic patients presenting to primary care a positive result is considered ≥10 mcgHb/gStool
     
  • When qFIT is used for the asymptomatic screening population (i.e NBCSP) a positive result is ≥100mcgHb/gStool.

 

Therefore, if a patient presents with symptoms which would normally trigger a qFIT, a recent negative screening result does not provide reassurance. A symptom based qFIT should be offered in this instance.

 

References

 

Page Review Information

Review date            02 September 2025      

Next review date     01 May 2026          

GP Sifter                 Dr Rebecca Hopkins    

Contributor              Ms Melanie Feldman, Colorectal Surgeon, Royal Cornwall Hospitals NHS Trust

       Commissioning Manager, Cornwall and Isles of Scilly ICB

        Karen Cock, Colorectal Consultant Nurse, Royal Cornwall Hospitals NHS Trust