Rectal bleeding: Can I use a FIT?

Key points

• Guidance now recommends the use of a FIT in cases of rectal bleeding as a it detects a breakdown of haemoglobin rather than fresh blood.??

• Evidence from the NICE FIT study has found that a FIT is 99.9% effective at ruling out suspected colorectal cancer in patients with rectal bleeding.?

• Advise patients to collect the FIT sample from a non-bloody stool or from a section without visible blood.??

• When a patient presents with rectal bleeding, review their risk factors, associated symptoms and carry out a rectal examination. Review whether the rectal bleeding is ‘unexplained’.??

A Faecal Immunochemical Test (FIT) detects small amounts of blood in stool which can be a sign of colorectal cancer. The test is used in bowel cancer screening and as an investigation for patients with signs and symptoms of possible bowel cancer.?

Guidance now recommends the use of a FIT in cases of rectal bleeding as a FIT detects a breakdown of haemoglobin rather than fresh blood.??

Evidence from the NICE FIT study has found that a FIT is 99.9% effective at ruling out suspected colorectal cancer in patients with rectal bleeding given its high sensitivity (96.6% at a cut-off of 10 μg/g.)??

Pitfalls

• Patients may be subject to unnecessary invasive investigations if they are not counselled on the appropriate way to obtain a FIT sample in cases of rectal bleeding.???

• Advise patients to collect the FIT sample from a non-bloody stool or from a section of stool without visible blood if this is not possible.?

• Do not be reassured when a patient has had a negative FIT test as part of the bowel cancer screening programme, as these FIT kits are not as sensitive as those provided in primary care.?

• The FIT threshold within screening is 120μg Hb/g whereas the symptomatic threshold is 10μg Hb/g.?

Helpful hints

NICE recommends the use of a FIT in the following cases of rectal bleeding:?

• Aged under 50 with rectal bleeding and unexplained abdominal pain or weight loss.?

• Aged 50 and over with unexplained rectal bleeding.?

Ensure that you review the patient’s history, risk factors, and carry out a rectal examination.??

If a patient has a potential cause of rectal bleeding on examination, such as haemorrhoids:?

• Still consider a FIT test if they have associated red flag symptoms as per guidance.??

• If they have no associated symptoms or risk factors, careful safety netting is vital for them to return if their symptoms do not settle, worsen, or they develop associated red flag symptoms. Consider the use of a symptoms diary.?

When requesting a FIT, ensure a careful safety-netting plan is in place to support the patient in returning the sample. You can utilise the NHSE/Accurx text reminder pathway.?

Consider a referral for suspected colorectal cancer if there is a strong clinical suspicion and the patient either does not return the FIT or is unable to complete the sample. Outline the reason for not having a FIT result on the referral form.?

Refer a patient on a suspected cancer pathway for colorectal cancer if a patient has a FIT result of at least 10μg Hb/g.?

If a patient’s FIT result is <10μg Hb/g and they have a normal full blood count and there is no ongoing clinical concern, safety net in primary care.?

If a patient’s FIT result is <10μg Hb/g and they have on-going symptoms they may require onward referral. Remember to consider other cancers or utilise a non-specific symptoms pathway.?

A FIT is not required in patients presenting with a rectal mass or ulceration. You can refer immediately on a suspected cancer pathway for colorectal cancer.?

Practice takeaway

NHSE has produced a FIT reminder pathway with Accurx which sends a reminder message on the day of the appointment and a further reminder three days later.?

The text also provides the patient with advice on how to complete the stool sample.?

Accurx has provided a step-by-step guide and short video on how to schedule these messages.

Find out more:

• Colorectal cancer course | GatewayC
• FIT course | GatewayC?
• Lower GI podcast | GPs Talk Cancer?
• FIT resources for England | GatewayC
• Nice guidance [DG56]: Quantitative faecal immunochemical testing to guide colorectal cancer pathway referral in primary care | NICE
• Guidance on faecal immunochemical testing (FIT) to help diagnose colorectal cancer among symptomatic patients in primary care | British Journal of General Practice
• FIT Symptomatic webpage | Cancer Research UK
• Screening vs symptomatic FIT pathway guides: England, Wales, Scotland, Northern Ireland | Cancer Research UK