Questions about the stool FIT test · Patient Guide
Can Piles Cause a Positive FIT Test?
Yes, they can. The harder question is whether piles caused your result, and the only way to answer that is to look at the bowel.
Written and medically reviewed by Mr Trif Papettas FRCS, Consultant Colorectal and General Surgeon and JAG dual-accredited endoscopist, Nuffield Health Warwickshire Hospital, Leamington Spa. Last reviewed .
Key points
- Bleeding piles can make a FIT positive.
- Piles are common and often exist alongside polyps or cancer, so having piles does not explain a positive result on its own.
- A positive FIT still needs a colonoscopy, or a similar test, to find the source, even if you know you have piles.
- If your piles are bleeding when the kit arrives, wait for the bleeding to settle, and see your GP if it does not.
- If colonoscopy finds only piles, they can be treated, often simply.
Can piles really cause a positive FIT?
Yes. Piles (haemorrhoids) are swollen blood vessels at the lower end of the rectum and anus, and blood from them can be picked up by a FIT. But piles cannot be assumed to be the cause of a positive result, so the bowel still needs to be examined.
NHS screening services say that if your piles are active when you do the kit, an abnormal result is more likely. A study from Korea of almost 4,000 people who had a colonoscopy after FIT found that piles were significantly linked to false-positive results: of 1,303 people with piles, 81 had a positive FIT explained by piles alone.
Why can piles turn a FIT positive?
FIT is most sensitive to bleeding from the lower bowel, and piles sit at the very end of it.
FIT detects globin, part of the haemoglobin in human blood. Blood from the stomach and upper bowel is mostly broken down by digestion before it reaches the sample, so FIT picks up bleeding from the colon, rectum and anal canal best. Blood from piles can coat the stool as it passes.
That same feature is what makes FIT useful. Polyps and cancers of the colon and rectum bleed into the same sample, and the test cannot tell the sources apart.
Why can’t a positive FIT just be put down to piles?
Because piles are common, and having them does not protect you from anything else.
Piles become more common with age, and so do polyps and bowel cancer. Many people have both. An examination in clinic can show piles, but it cannot see the colon. In the Korean study above, almost 1 in 4 people with a positive FIT had an advanced polyp or a cancer.
What piles can explain
- Bright red blood on the toilet paper or on the surface of the stool
- Itching, or a lump that comes down and goes back
- Discomfort after opening your bowels
- A positive FIT, once the rest of the bowel has been checked
What piles don’t explain
- Iron-deficiency anaemia
- A lasting change in bowel habit
- Weight loss you cannot explain
- Darker blood mixed into the stool
- Abdominal pain or a lump in the abdomen
This is a guide, not a way to diagnose yourself. Bleeding that looks like it comes from piles can come from higher up. See when rectal bleeding needs a colonoscopy.
What if my piles are bleeding when the FIT kit arrives?
Wait for the bleeding to settle before doing a screening kit, and see your GP if it does not settle within a week or two.
- Screening kit: wait until the bleeding has settled. If it does not settle within a week or two, see your GP rather than putting the kit off. Instructions and the helpline number are in the kit.
- Kit from your GP: tell the practice. If you have visible bleeding, they may refer you without waiting for a FIT.
- Either way: bleeding that keeps happening needs assessing in its own right, whatever the FIT later shows.
FIT kits also ask you not to take a sample during a period.
What happens at colonoscopy if I have piles?
Colonoscopy examines the whole large bowel, and piles are usually seen at the end of the test. Having piles does not make it harder or riskier.
The camera examines the bowel from the rectum to the start of the colon. Piles are usually seen at the end, when the camera is turned to look back at the lower rectum. Polyps can usually be removed during the same test, and samples taken from anything abnormal. Tell the endoscopist if your piles are sore so extra care can be taken. If you are anxious about the test, read do I need a colonoscopy?
What if colonoscopy shows it’s only piles?
That is a good result, and a common one. The piles can then be treated on their own merits.
Once the rest of the bowel is shown to be clear, treatment can start with more fibre and fluid and avoiding straining. If needed, a procedure such as banding, or an operation for larger piles, can follow. Your screening centre or doctor will tell you when any future testing is due. Mr Papettas both performs colonoscopy and treats piles, so the bleeding can be investigated and treated by the same consultant. See Private haemorrhoid treatment in Warwickshire for the options.
Frequently asked questions
I know I have piles. Do I really need a colonoscopy after a positive FIT?
Yes. Piles can cause a positive FIT, but they often exist alongside polyps or cancer, and the test cannot tell the sources apart. A colonoscopy is the way to find out where the blood came from.
Can a doctor just examine my bottom instead of doing a colonoscopy?
An examination can confirm that you have piles, but it cannot see the colon, where polyps and most bowel cancers develop. It does not replace a colonoscopy after a positive FIT.
Will having piles stop me having a colonoscopy?
No. Piles do not make colonoscopy harder or riskier. Tell the endoscopist if they are sore so that extra care can be taken.
Should I treat my piles and then repeat the FIT?
No. A repeat FIT does not cancel out a positive one, and treating piles does not change the need to examine the rest of the bowel. Treat the piles once colonoscopy has shown the rest of the bowel is clear.
Can piles turn into cancer?
No. Piles are swollen blood vessels and do not turn into cancer. The concern is not the piles themselves but that they can hide another source of bleeding.
What other non-cancerous conditions can cause a positive FIT?
An anal fissure, bowel inflammation such as colitis, diverticular disease and non-cancerous polyps can all cause a positive FIT. Blood from a period can also contaminate a sample, which is why kits ask you not to take one during a period.
Sources
- Kangbuk Samsung Hospital: Are hemorrhoids associated with false-positive fecal immunochemical test results?
- Harrogate and District NHS Foundation Trust: Bowel cancer screening frequently asked questions
- NICE HTG690 (formerly DG56): Quantitative faecal immunochemical testing to guide colorectal cancer pathway referral in primary care
- Monahan KJ et al. Faecal immunochemical testing (FIT) in patients with signs or symptoms of suspected colorectal cancer: a joint ACPGBI/BSG guideline. Gut, 2022
This page is general information, not a diagnosis. It was written and medically reviewed by Mr Trif Papettas FRCS on 26 October 2026 against current NICE, NHS England and British Society of Gastroenterology guidance. Next review due October 2027, or sooner if that guidance changes. If you have new or worsening symptoms, speak to your GP or book a consultation. If you have heavy bleeding, black stools, severe abdominal pain or feel faint, call 999 or go to A&E.
Related reading
Positive FIT and known piles?
Mr Trif Papettas FRCS performs colonoscopy and treats piles himself, so the bleeding can be investigated and, if it is only piles, treated by the same consultant. Colonoscopy can usually be arranged within days at Nuffield Health Warwickshire Hospital, Leamington Spa.
Self-referrals welcome · No GP letter required · Self-pay and insured patients seen at Nuffield Health Warwickshire Hospital, Leamington Spa CV32 6RW · Serving Leamington Spa, Warwick, Kenilworth, Stratford-upon-Avon and Coventry