Polyps / Colon Polyps

Polyps / Colon Polyps

A colon polyp is a growth from the internal lining of the bowel. Polyps may be just a few millimetres in size to several centimetres across when they are detected at colonoscopy. Most polyps appear as small raised areas but larger polyps can look like grapes on narrow stalks or patches of shag pile carpet.

Why Are Polyps Important?

If not removed, some polyps may grow and eventually lead to cancer. Most polyps grow slowly and cancer is rare in polyps less than 1cm in diameter. It usually takes many years for a small polyp to turn in to a cancer but occasionally cancer can develop in a small polyp.

What Causes Polyps?

Colon polyps and colon cancer are very common in New Zealand. Genetic factors are important and our low fibre diet containing large quantities of burnt meat increase the risk.

What Are The Symptoms Of Polyps?

Most Polyps are small and cause no symptoms at all. Larger polyps may cause bleeding or occasionally diarrhoea or even a blockage in the bowel.

How are polyps removed?

Most polyps can be removed at the time of colonoscopy, this is called polypectomy. Rarely surgery is required. At colonoscopy small instruments can be passed down the colonoscope to remove a polyp. Small (<5mm) polyps are often destroyed by grabbing the polyp with biopsy forceps and burning it with an electric current, this is called “hot biopsy”. Larger polyps are usually removed with a snare that lassoes the polyp and cuts it away from the normal tissue again using an electric current.

What are the complications of Polypectomy?

Most often there are no complications of removing a polyp at the time of colonoscopy but you need to seek urgent medical attention if you develop any of the following:

  • Bleeding – this can happen immediately following the procedure or may occur several days later. A small trace of blood following the polypectomy is no cause for concern but large amounts of blood should not be ignored.
  • Abdominal Pain – abdominal bloating and discomfort immediately following a colonoscopy is not uncommon but is usually not severe and resolves rapidly as flatus is passed. Severe pain and tenderness may indicate a leak from the bowel and should be investigated with an abdominal x-ray.
  • Fever – a fever, particularly if associated with abdominal pain may indicate a leak from the bowel and a CT scan is usually required to investigate this.

What follow-up is required?

After the polyp is removed it is sent to the laboratory and is examined by a pathologist. A report is sent to your colonoscopist and your GP. Depending on that report and your personal / family history a further colonoscopy may be scheduled. If the polyp is small and there is no evidence of cancer the repeat colonoscopy is usually in 3-5 years time to look for further polyps that may develop. If the polyp was large, contained cancer, or if there were lots of polyps an earlier repeat colonoscopy may be recommended. If the polyp removed was not the sort of polyp that would ever have turned in to a cancer a repeat colonoscopy may not be necessary. If the polyps are removed at colonoscopy they are no longer a risk for developing colon cancer