Faecal Occult Blood Testing (FIT)
FIT can be requested for symptomatic patients who do not meet the criteria for referral on the Lower GI cancer 2WW pathway.
Several lower gastrointestinal symptoms can suggest colorectal cancer, including rectal bleeding, a change in bowel habits, weight loss, anaemia, abdominal pain, blood in stools (faeces) and unexplained thrombocytosis.
Thrombocytosis – a new criteria to request symptomatic FIT test (June 2019)
The Symptomatic FIT request form has been updated to include unexplained Thrombocytosis as a criteria to request a FIT test.
Unexplained thrombocytosis will be indicated by two results of raised platelets taken two weeks apart (not associated with a known predisposing factor such as infection, trauma or postoperative)
Where blood in stools is not visible (faecal occult blood) FIT tests can be used to detect its presence.
These sensitive human globin detecting faecal occult blood tests can be used in Primary Care to assess those patients at a low risk of colorectal cancer and help determine with a positive result whether they should be referred for further investigations where they do not meet the criteria for a 2WW referral in NICE’s guideline on suspected cancer.
Guidance about requesting the test (using the APPROVED FORM)
- Please see ‘FIT symptomatic pathway’ in the ‘Useful documents’ tab to the right for information on how the test is administered
- Patient Information Leaflet is available in the ‘Useful documents’ tab to the right – please print and give to the patient.
- The result will be sent to you electronically and is either positive or negative
- GPs retain responsibility for acting on the outcome of the test result
- You will be informed if the patient does not complete the test within 2 weeks
- A patient with a positive test should then be referred using the existing Lower GI 2 Week Rule
A negative test does NOT completely rule out the possibility of colorectal cancer.
FIT results of more than 10 are deemed positive – patient has a 1 in 4 chance of Lower GI cancer.
When FIT is less than 10 it suggests a low probability of Lower GI cancer, although these do occur. Patients with bowel cancer and a FIT less than 10 often have other symptoms.
GPs should reassess the patient clinically in the light of the result, and either seek advice from the Colorectal Department or employ ‘safety netting’ with the patient
Please complete the FIT request form on your clinical system and forward to :
firstname.lastname@example.org via NHS Mail
GP Guidance on Requesting FIT Testing
Information about FIT:
- FIT detect human globin by means of an antibody-based assay.
- The FIT sampling technique is simpler and easier to collect compared to that of original guaiac-based FOBT (gFOBT)
- Only ONE sample is required and no dietary or medication restrictions are needed prior to the test
- Overall accuracy of FIT for detection of CRC was 95% with 79% sensitivity and 94% specificity, as has been shown in systematic review and meta-analysis including 19 qualified studies performed by Lee et al
- FIT has been shown to have a greater sensitivity in detecting advanced adenomas and CRC than the guaiac-based gFOBT
Allison JE, Fraser CG, Halloran SP, Young GP. Population screening for colorectal cancer means getting FIT: the past, present, and future of colorectal cancer screening using the fecal immunochemical test for hemoglobin (FIT) Gut Liver. 2014;8:117-130.