Bowel polyps

Also called Colonic polyps, Adenomas

Growths in the bowel that are usually harmless and are how most bowel cancers begin. Removing them is prevention that works.

What it is

Growths on the lining of the large bowel. Most are harmless, and most cause no symptoms.

They matter because the majority of bowel cancers develop from a particular kind of polyp, an adenoma, over roughly ten years. Finding and removing them prevents the cancer that would otherwise have followed.

That is the entire rationale for the NHS bowel cancer screening programme, which sends a home test kit to everybody in an eligible age range. It is one of the most effective preventive programmes in the health service, and uptake is well below where it should be, particularly among men, in deprived areas, and among people with a learning disability, for whom the kit is rarely adapted or explained.

The test is a stool sample done at home. Most people who complete it need nothing further; a positive result leads to colonoscopy, and most colonoscopies find either nothing or polyps that are removed there and then.

Some people have an inherited condition, familial adenomatous polyposis or Lynch syndrome, causing many polyps and a very high cancer risk, needing surveillance from a young age and sometimes preventive surgery.

After polyps are removed, surveillance colonoscopy at an interval based on the findings is standard.

Signs you might notice

Usually none at all, which is why screening exists.

When present: blood in the stool, either visible or detected on a test; a change in bowel habit lasting three weeks; mucus in the stool; and rarely, abdominal pain or anaemia.

Urgent, and needing referral rather than screening: visible blood in the stool; a change in bowel habit for three weeks or more; unexplained weight loss; a lump in the abdomen; or unexplained iron deficiency anaemia, particularly in a man or a post-menopausal woman.

Screening is for people with no symptoms. Symptoms need investigating in their own right, and a recent negative screening test does not change that.

A family history of bowel cancer in a close relative under 50, or several affected relatives, is a reason to ask about earlier and more frequent screening.

How it can affect day-to-day life

The barriers to completing the home test kit are practical and social: squeamishness, not understanding the instructions, not having a private toilet, and simply putting it off. Talking about it plainly, and helping somebody do it, converts a leaflet into a completed test.

For people with a learning disability, easy-read instructions and support to complete the kit make the difference between screening and no screening, and it is a recognised inequality.

Bowel preparation before colonoscopy is the part people dread most and is worth explaining honestly, including practical advice about staying near a toilet and what to eat beforehand.

Being told polyps were found and removed is often heard as having had cancer. The accurate framing is that something that might have become cancer in ten years was removed, which is a good outcome.

Surveillance intervals are set by guideline and are worth writing in a diary, because recall systems fail.

Supporting someone well

Do the screening test when it arrives. It is the single most effective thing in this entry.

Help somebody who finds it difficult: read the instructions with them, use easy-read versions, and make it a task with a date.

Do not use a recent negative screening test to explain away symptoms; symptoms need separate investigation.

Get visible blood, a change in bowel habit for three weeks, or unexplained anaemia referred.

Ask about family history and whether earlier screening is indicated.

Keep the surveillance colonoscopy appointment after polyps are removed, and write the interval down.

Reduce risk where possible: stop smoking, reduce alcohol and processed meat, keep active, and treat obesity.

Ask about Lynch syndrome testing where there is a strong family history.

Where to get help

The NHS bowel cancer screening programme, which sends kits automatically and has a freephone helpline.

A GP practice for symptoms, regardless of screening status.

Bowel Cancer UK run an ask-the-nurse service.

Guts UK for information on bowel health.