Private bowel screening versus the NHS FIT kit

If you have rectal bleeding, black stools, a lump in the abdomen or rectum, unexplained weight loss, or a bowel habit that has changed and stayed changed, this is the wrong page to wait on. See a GP the same day, use an urgent suspected-cancer pathway if you are offered one, and use 999 or A&E if you are collapsing, in severe pain, or bleeding heavily. NICE suspected-cancer guidance (NG12) treats those symptoms as a reason to investigate, not as a reason to wait for a screening kit. A private diary date does not replace that.

The NHS FIT kit and a private bowel package are built for people who feel well enough to be screened. They look for hidden blood, inflammation and, in some private bookings, structure. They are not a diagnosis. A flag on a stool test, a calprotectin result or a CT colonography report still has to be read by a doctor. The Health Screening Clinic has done that kind of doctor-led work at 117a Harley Street since 1984, and it is CQC registered. None of that turns a preventative visit into a substitute for emergency care.

What the NHS FIT programme is

NHS.uk describes bowel cancer screening as a home test offered to people aged 50 to 74. If you are registered with a GP you are sent a faecal immunochemical test kit through the post every two years. You scrape a small sample of faeces onto a stick, post it, and usually receive a letter within two weeks. People aged 75 and over can ask for a kit on 0800 707 6060.

The UK National Screening Committee recommended that programme, including the expansion down to age 50, because the evidence for that age band showed more benefit than harm. The test looks for hidden blood. Blood can come from a polyp, from cancer, from piles, from a fissure, or from nothing that will ever matter. NHS.uk is plain that a result saying further tests are needed does not mean you have cancer, and that no further tests needed does not mean you cannot have bowel cancer now or later.

A screening FIT is not the same number as a symptomatic FIT. NICE NG12, drawing on its HealthTech guidance on quantitative FIT in primary care, uses a threshold of 10 micrograms of haemoglobin per gram of faeces to guide urgent colorectal referral in people who already have symptoms such as a change in bowel habit, iron-deficiency anaemia, or unexplained rectal bleeding. The NHS screening programme in England has used a higher threshold, 120 micrograms per gram, and the UK NSC recommended lowering that screening threshold to 80 micrograms per gram. NHS England is rolling that change through in phases, aiming to finish by March 2028. Wales and Scotland have already used 80. Mixing those two thresholds is how people think a screening letter has ruled symptoms out.

The UK NSC defines screening as identifying apparently healthy people who may have an increased chance of a condition. Tests offered to large groups tend to be simple rather than very accurate, and they often need further tests. Paying privately does not sit outside those limits.

What a negative or positive FIT is not

A negative screening FIT means hidden blood was not found above the programme threshold in that sample. It is not a clean bowel, and it is not permission to sit on rectal bleeding that starts the week after the letter. Keep the invitation when it comes.

A positive screening FIT means blood was found above the threshold. You are then invited to a specialist nurse and, usually, to a colonoscopy, which can see the lining and remove polyps. Private CT colonography is a different instrument. It can show structure without a camera in the bowel. It cannot remove a polyp on the table.

If a GP has already asked you for a FIT because of symptoms, that sample is NICE NG12, not the screening programme. Do not swap it for a private screening wait, and do not assume a private QFIT has closed the NHS conversation.

What private bowel screening can add, and what it cannot

Private bowel screening is a doctor-led package, not a posted envelope.

At The Health Screening Clinic the Essential bowel screen currently costs £499. It includes a consultation with a lifestyle and risk assessment, quantitative FIT with calprotectin, a blood panel that includes iron and haemoglobin, and an in-person review of the results. Most results are ready in three to five working days. That is a different job from the NHS kit, because a doctor has taken a history, looked at iron and anaemia, and added calprotectin, an inflammation marker used more for bowel inflammation than as a cancer test.

Calprotectin can be raised in inflammatory bowel disease, infection and other non-cancer causes. Iron and haemoglobin can flag anaemia that NICE already treats as a colorectal prompt. None of those numbers is a diagnosis. A flag means look again with the history and, if needed, with pictures.

The Elite bowel screen currently costs £2,499. It keeps the consultation, QFIT and calprotectin, then adds enhanced bloods with CEA, CRP, full iron studies, B12, folate and a metabolic panel, expanded stool tests (FIT, FOBT, calprotectin and elastase when requested), CT colonography, and a same-day colorectal surgeon. FOBT is an older blood-in-stool method. Elastase looks at pancreatic enzyme output. CEA is used mainly in known bowel cancer, not as a population screen.

This is not a colonoscopy-price page. Optical colonoscopy remains the investigation that can biopsy and remove. CT colonography images the colon without that camera, uses ionising radiation, can miss flat lesions, and can find extra-colonic things that then need explaining. A radiologist reports the scan. The surgeon is there to read that report with the stool tests and bloods, not to sell a theatre slot.

A private package does not replace the NHS programme if you are eligible. Keep posting the kit. Private work is extra information for a doctor, including if you are under 50, over 74, or between invitations.

How this sits beside a Health MOT

A Health MOT is a wide preventative assessment. Every tier includes a GP examination, bloods, a report and a review. None of that is a dedicated bowel protocol. CEA on an Elite MOT is still a marker, not a FIT. Full-body MRI on Ultimate is a weak look at the bowel lining. If the question is bowel, book bowel screening rather than hoping a MOT will stand in for stool tests and, where needed, CT colonography.

The cancer screening list is organised by organ for that reason. A MOT can sit beside an organ package. It should not be used as a quieter way of avoiding a stool sample. If a result is outside range, that flag is not a diagnosis. The doctor who took the history decides whether to repeat, watch, add imaging, or refer.

Tips and tricks

• Do the NHS FIT kit when it arrives if you are aged 50 to 74, and ask for one at 75 or over if you still want the programme.
• A posted kit and a private consultation are different jobs.
• Complete the NHS sample as the leaflet describes.
• Name symptoms before you name a package.
• Bleeding, weight loss or a bowel habit that has shifted need a GP now.
• Bring previous FIT letters, colonoscopy reports and iron studies.
• Ask which stool tests you are having, and whether CT colonography is in the booking.
• Leave three to five working days for results, and keep the review.

Things to avoid

• Do not sit on rectal bleeding, unexplained weight loss, black stools or a new mass because a screening kit is in the post or a private appointment is already booked. That needs a GP, an urgent pathway or 999, not a screening wait.
• Do not treat a negative NHS FIT as proof that you do not have bowel cancer.
• Do not treat a positive FIT as a cancer diagnosis.
• Do not mix the screening threshold with the NICE symptomatic threshold of 10 micrograms per gram.
• Do not skip the NHS invitations you are eligible for because you have paid for a private QFIT.
• Do not read CEA, calprotectin or a CT colonography report as an all-clear or as a verdict.
• Do not treat this page as a comparison of optical colonoscopy prices.
• Do not book a general MOT and hope it will inspect the bowel lining. Or book at The Health Screening Clinic on 020 7183 7056.

If you also want a wider preventative look, use the Health MOT tiers as a separate booking rather than as a substitute stool test.

If you want a doctor-led bowel package rather than an envelope on its own, review the current bowel screening packages on the bowel cancer screening page.

For why a CEA blood test is not a bowel screen, read can a blood test detect cancer. For choosing between organ packages and wider screening, see whole-body cancer screening versus an organ package.

Frequently asked questions

Is private bowel screening a replacement for the NHS FIT kit?

No. The NHS programme invites people aged 50 to 74 every two years with a home kit. A private package can add a doctor, bloods, calprotectin and, at Elite, CT colonography and a colorectal surgeon. Keep the NHS invitation if you are eligible.

I have rectal bleeding or unexplained weight loss. Should I wait for a FIT kit or a private screen?

No. See a GP, use an urgent pathway if you are offered one, and use 999 or A&E for emergencies. NICE NG12 treats those symptoms as a reason to investigate now. Screening is for people who feel well enough to be screened.

Does a negative FIT mean I do not have bowel cancer?

No. NHS.uk says a result of no further tests needed does not always mean you do not have bowel cancer, and it does not stop you getting it later. Get new symptoms checked even after a reassuring letter.

What does the Essential bowel package include?

Currently £499 at 117a Harley Street: consultation, quantitative FIT with calprotectin, bloods including iron and haemoglobin, and an in-person review. Results are usually ready in three to five working days. A flag is not a diagnosis.

What does Elite add?

Currently £2,499. It adds enhanced bloods including CEA, CRP, iron studies, B12, folate and a metabolic panel, expanded stool tests (FIT, FOBT, calprotectin and elastase when requested), CT colonography, and a same-day colorectal surgeon. It is not an optical colonoscopy, and it is not priced as one.

Is CEA a bowel cancer blood test I can rely on?

No. CEA can be raised for non-cancer reasons and normal with early bowel cancer. NICE uses it mainly in follow-up of known disease, not as a population screen. The NHS programme uses stool FIT, not CEA.

Do I need a GP referral?

No. The clinic at 117a Harley Street has been doctor-led since 1984, is CQC registered, and accepts self-referral. Symptoms still belong with a GP first.

Sources

• NHS. Bowel cancer screening
• UK National Screening Committee. Principles of screening
• UK National Screening Committee. More sensitive bowel cancer screening test implemented
• NICE. Suspected cancer: recognition and referral (NG12)
• NICE. Quantitative faecal immunochemical testing to guide colorectal cancer pathway referral in primary care
• GOV.UK. NHS bowel cancer screening programme
• General Medical Council. Medical register, Penelope Sheehan, 6056535

Written By

Stephen Lingam

Managing Director

Managing Director of Medical Express Clinic and the Health Screening Clinic since 1984. Over 40 years of operational experience in private healthcare on Harley Street, overseeing patient care, clinical standards, and service delivery.

Medically Reviewed

Dr Penny Sheehan

MBBS, MRCGP

General Practitioner

GMC: 6056535

Specialising in women's health, hormonal balance, and menopause management within screening contexts.

Last reviewed: 25/09/2026