Bowel Cancer

Bowel cancer - also known as colorectal cancer or colon cancer - is any cancer that affects the colon (large bowel) and rectum (back passage).

Most bowel cancers start as benign innocent growths - called polyps - on the wall of the bowel. Polyps are like small spots or cherries on stalks and most do not produce symptoms. Polyps are common as we get older and most polyps are not pre-cancerous.

One type of polyp called an adenoma can become cancerous (malignant). If left undetected the cancer cells will multiply to form a tumour in the bowel.

If untreated, the tumour can grow into the wall of the bowel or back passage. Once cancer cells are in the wall, they can travel into the bloodstream or lymph nodes; from here the cancer cells can travel to other parts of the body. For bowel cancer, the most common places for bowel cancer cells to spread to are the liver and the lungs. The process of spread is called metastasis.

The earlier bowel cancer is caught, the easier it is to treat. 75% of bowel cancer is curable if caught early. This why it is so important to know the symptoms and causes of bowel cancer.

The first step you can take to protect against bowel cancer is to be aware of the symptoms. And most importantly, see your GP if you are at all concerned.

  • Bleeding from the bottom (rectal bleeding) without any obvious reason. Or if you have other symptoms such as straining, soreness, lumps and itchiness.
  • A persistent change in bowel habit going to the toilet more often or experiencing looser stools for several weeks.
  • Abdominal pain especially if severe.
  • Any lumps or mass in your tummy.
  • Weight loss and tiredness (a symptom of anaemia).

There are three main types of treatment for bowel cancer - surgery, chemotherapy and radiotherapy. Depending on the stage and location of your cancer, you will usually receive one, or a combination of these treatments. People with Bowel cancer can also receive monoclonal antibody treatments if the bowel cancer has spread to other parts of the body.


Surgery is performed to remove the segment of the large intestine which contains the cancer. At the same time the surgeon removes 10 to 20 lymph glands which lie close to the cancer in order to examine these under the microscope and determine whether the cancer has started to spread beyond the bowel. Most bowel cancers can be removed without the need for a permanent colostomy bag but if the cancer is low in the rectum a colostomy may be required.


Chemotherapy, or drug treatment for cancer, is commonly recommended following surgery if the cancer has spread to the adjacent lymph glands. Spread to the lymph glands indicates that there is also a possibility that the cancer may a have spread through the blood system to other parts of the body and chemotherapy is given to help to kill any small but invisible areas of remaining cancer. If areas of bowel cancer are visible outside the bowel on x-rays or scans [bowel cancer secondaries or metastases] this is a more serious situation and chemotherapy or monoclonal antibody therapy are used to control the cancer rather than cure.


Radiotherapy is a powerful X-ray beam which can also be used to control bowel cancer secondaries and relieve symptoms. However, radiotherapy is also used as part of the initial, curative treatment for rectal cancer. Cancers in the rectum can spread in small quantities to the walls of the pelvis and radiotherapy is given to the pelvic area to kill any areas of cancer that have spread to the pelvis.