Polyps: what they are, symptoms, causes and treatment

The symptoms of a polyp depend on where it is growing and how big it is, and many polyps cause none at all. The table summarises what NHS and NHS inform pages and NHS trust leaflets say for the most commonly searched sites.

A polyp is an overgrowth of tissue that sticks out from the surface of the lining of part of the body. It may look like a small bump, or like a grape on a stalk. NHS inform describes the bowel version as a tiny raised area or bulge (sessile), a polyp that looks like a grape on a stalk (pedunculated), or many tiny bumps clustered together.

The word covers very different things. A bowel polyp and a nasal polyp share little apart from their name, and the risks and treatments depend on the site. The sections below cover the four sites for which UK patient information is most readily available.

The NHS describes bowel polyps as small growths on the lining of the large intestine (colon) or rectum. They are very common and not usually serious, but sometimes they can lead to bowel cancer. NHS inform says they are common, affecting 15 to 20 percent of the UK population, are not usually cancerous, and tend to occur in people over the age of 60.

The exact cause is not known. The NHS says it is thought they are caused by the body producing too many cells in the lining of the bowel, and that you may be more likely to develop polyps if a family member has had bowel polyps or bowel cancer, you are over 50, you have inflammatory bowel disease, or you are overweight or smoke.

Bowel polyps are usually found during a colonoscopy, a CT colonography or bowel cancer screening. The NHS says they are usually removed during the colonoscopy with a wire loop that cuts off or burns off the polyp, which is painless. Rarely, when there are lots of polyps or one is very large, surgery may be needed to remove part of the bowel. Removed polyps are sent to a laboratory to check that the polyp has been completely removed, whether there is any risk of it regrowing and whether there are cancerous changes.

NHS inform says some people will need further colonoscopies because polyps can recur, and that you might be asked to have repeat examinations at intervals of around 3 to 5 years.

The NHS describes nasal polyps as painless, soft growths inside the nose. They are not usually serious, but can keep growing and block your nose if not treated. It is not clear what causes them, but asthma and an intolerance or sensitivity to aspirin increase the risk. They are rare in children.

A GP should be able to tell if you have nasal polyps by looking inside your nose. You will usually be given steroid nose drops or spray to shrink the polyps, and sometimes steroid tablets, usually for up to 2 weeks. If there is no sign of improvement after about 12 weeks, the GP may suggest surgery. The NHS says most people who have surgery see an improvement, but it is common for polyps to grow back, usually within a few years.

A pharmacist can recommend steroid nasal sprays that do not need a prescription and salt water washes to help unblock the nose. The NHS says these washes are not suitable for children.

An NHS trust leaflet describes a cervical polyp as a growth of tissue from the outside of the cervix (neck of the womb) or inside the cervical canal. It says one in ten women will have one in their lifetime, that the cause is unknown, and that most are benign but very rarely contain abnormal cells that need further treatment.

There are often no symptoms and the polyp is often noticed during a cervical screening test or an internal examination. Because the polyp may have blood vessels running through it, it can cause bleeding after sex, between periods or after the menopause. Occasionally it can make it more difficult to get an adequate cervical screening sample.

A cervical polyp is usually easily removed in an outpatient clinic. Small polyps can be twisted off the cervix without local anaesthetic, and larger polyps may need a local anaesthetic and a heated wire loop. Leaflets describe some discharge or light bleeding for a few days or up to two weeks, and advise using sanitary towels rather than tampons and avoiding sex for about a week. Removed polyps are sent to a laboratory.

An NHS hospital leaflet describes polyps in the womb as skin-tag-like structures that grow from the lining of the womb and can cause period problems, bleeding between periods or bleeding in menopausal women. When a polyp is seen during a hysteroscopy (a look inside the womb with a thin telescope) the gynaecologist will offer to remove it.

The leaflet says the procedure takes about 10 to 15 minutes, can be done safely in an outpatient clinic without a general anaesthetic, and that polyp removal itself is usually painless and very quick. It adds that even without bleeding problems it is advisable to remove polyps to check there is no cancer, and that polyps are also removed in some postmenopausal women to make sure there are no tissue changes such as cancer.

The test depends on the site. For the bowel, the NHS says a GP may recommend a colonoscopy, in which a long, thin flexible tube with a camera is guided up into the bowel, or a CT colonography, an X-ray based scan of the bowel. For the nose, a GP can usually tell by looking inside. For the cervix, a polyp may be noticed at a screening test or internal examination. For the womb, hysteroscopy is used.

In every site the tissue is the final answer: removed polyps are sent to a laboratory so that a specialist can say exactly what they are, whether they have been completely removed and whether any cancerous change is present.

For possible bowel polyps, the NHS says to ask for an urgent GP appointment or get help from NHS 111 if you have had diarrhoea for more than 7 days, your poo is black or dark red, or you have bloody diarrhoea.

It says to go to A&E or call 999 if you are bleeding non-stop from your bottom, or there is a lot of blood, for example the toilet water turns red or you see large blood clots. For nasal polyps, see a GP if you have difficulty breathing or your symptoms are getting worse.

A polyp is a description of a shape, not a diagnosis, and other conditions can produce similar symptoms. The table shows how the main bowel and nasal symptoms overlap with other conditions named in the NHS pages.

Most polyp pathways on the NHS begin with a GP: for the bowel, a referral for colonoscopy or CT colonography, and bowel cancer screening also finds polyps; for the nose, treatment with sprays and, if needed, referral for surgery; for the cervix and womb, referral to gynaecology for removal, often as an outpatient.

Private colonoscopy, ENT and gynaecology clinics can arrange the same tests and removal procedures, often with quicker access. The procedures are broadly the same, so ask who will explain the laboratory result and whether a repeat test is planned.