Colorectal polyps

What are colorectal polyps?

Colorectal polyps, also known as bowel polyps or colonic polyps, are small abnormal growths that can occur on the lining of the colon or rectum wall.1,2

The majority of polyps commonly measure from a few millimetres to one centimetre in size, and can either be flat or have a stalk.

While they are mainly benign, if left untreated for many years colorectal polyps can become malignant and develop into colorectal cancer. This will depend on the histological type of polyp, as outlined below.

  1. Tubular adenoma – lowest risk
  2. Tubulo-villous adenoma – medium risk
  3. Villous adenoma – highest risk

Polyps that are larger than two centimetres are also significantly more likely to become cancerous.

Signs and symptoms of colorectal polyps

Colorectal polyps rarely produce symptoms until they become large, however symptoms can include:1

  • Blood and mucus during bowel movements
  • A change in bowel motions (including increased frequency)
  • Pain and discomfort in the abdomen


The most common test for diagnosing colorectal polyps is a colonoscopy, which is used to examine the colon wall and remove polyps. While other diagnostic techniques include barium enema and CT colonoscopy, they are indirect methods and are unable to obtain tissue biopsies or remove polyps.


Treatment for colorectal polyps involves surgical removal (also known as a polypectomy) to ensure they do not develop into colorectal cancer. Many polyps are able to be removed during a colonoscopy.

However, you may need surgery to remove the polyps if they are large and can’t be removed during a colonoscopy. In most cases, this can be done by laparoscopic surgery.

Following the removal of colorectal polyps, it is recommended that surveillance colonoscopies are undertaken depending on the degree of cell change (dysplasia).


For a full list of references, click here.
  1. American Society of Colon and Rectal Surgeons. (2019). Polyps of the colon and rectum. Retrieved on 18 November 2019 from
  2. Gastroenterological Society of Australia. (2019). Bowel polyps. Retrieved on 18 November 2019 from

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