Bowel polyps (Colon polyps)

Bowel polyps are small growths on the inner lining of the colon (large bowel) or rectum.

Bowel polyps do not usually cause symptoms and are usually discovered as a result of a bowel investigation such as a colonoscopy. Polyps are usually less than 1cm in size, although they can grow up to several centimetres.

Bowel polyps are not usually cancerous, although they will need to be removed as some will potentially turn into cancer if left untreated. Some people have just one polyp, others may have several. Bowel polyps are most common in people aged over 60.


What causes the condition? The cause of bowel polyps is an abnormal production of cells. The bowel lining is constantly renewing itself, and a faulty gene can cause bowel lining cells to grow more quickly. There may also be a family tendency towards developing bowel polyps or even bowel cancer.

Bowel polyps occur more commonly in older people. Figures suggest around a quarter of people over the age of 50 develop at least one bowel polyp.

Usually people don’t know they have bowel polyps as mostly there are no symptoms. However, some larger polyps can cause a small amount of bleeding from the back passage, or mucus when you open your bowels. Less frequently, symptoms may include abdominal pain, diarrhoea or constipation.

Bowel polyps are usually diagnosed when the bowel is being investigated for other reasons. Procedures such as a sigmoidoscopy, a colonoscopy or screening for bowel cancer may reveal the presence of bowel polyps.

If you are diagnosed with a bowel polyp, even if you have no symptoms, you’ll probably be advised to have it removed. This is to avoid the very small risk of it developing into a cancer in the future.

Bowel polyps can be treated quickly and painlessly by removal, either during a colonoscopy or, in some cases, using a biopsy forcep. Sometimes bowel polyps will need to be treated by surgically removing part of the bowel.


A colonoscopy is a procedure to look at the lining of the back passage (rectum) and large bowel (colon).

What next?

If you are suffering with a suspected condition, you should seek the advice of your doctor who will be able to refer you to Benenden Hospital for diagnosis and treatment.

There are four ways to access treatment at Benenden Hospital which include self-funding, using private medical insurance or your Benenden membership, or through the NHS e-Referral scheme.