Bowel Cancer Treatment: Surgery, Chemotherapy & Radiotherapy

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Bowel Cancer

The bowel is an important part of the digestive system, which can be divided into the small bowel (or small intestine) and the large bowel (or the colon and rectum). The majority of bowel cancers is located in the large bowel and is thus also referred to as colorectal cancer. Bowel cancer usually starts in the innermost layer, the lining of the bowel, with the development of a small growth on the bowel wall, called polyp or adenoma.

This article discusses the main options for bowel cancer treatment, which are:

The type of treatment given to a certain patient depends on several factors, the most important ones of which are:

  • Type and size of the cancer
  • Age of the patient
  • Overall health of the patient
  • Spreading of the cancer
  • How abnormal the cancer cells look (also known as the ‘grade’ of the cancer)


The first and most often used treatment for bowel cancer is surgery. Which kind of surgery will be performed depends on:

  • The location of the cancer
  • The size of the tumor(s)
  • Whether or not the cancer has spread

The different types of surgery that can be performed include:

  • A local resection: If the cancer is in a very early stage, the surgeon will simply remove the cancer from the lining of the bowel.
  • A colectomy: Here, an incision in the abdomen will be made and the part of the colon containing the tumor will be removed. The lymph glands close to the colon will also be removed to make sure the cancer hasn’t spread to them.
  • An abdominoperineal resection: When the cancer is located in the lower part of the rectum, the surgeon will have to remove the anus and rectum completely. Then a permanent colostomy is made, opening up the abdomen. In this case, a stoma is necessary and permanent.


The second treatment discussed here is chemotherapy, which is used to treat bowel cancer in three circumstances:

  • Before surgery: Often, chemotherapy is administered before surgery, with the aim to shrink the cancer and make it easier to remove during surgery. This is called neo-adjuvant chemotherapy.
  • After surgery: Chemotherapy can also be given after surgery, in an attempt to prevent the cancer from coming back. This is called adjuvant chemotherapy.
  • When the cancer has spread: If the cancer has spread beyond or throughout the bowel, chemotherapy is administered since surgery would be too difficult.


The third bowel cancer treatment is radiotherapy, which uses high energy rays to combat cancer cells. Radiotherapy is not often used for cancers located in the colon, but it is a fairly popular option when the cancer is found in the rectum. Radiotherapy is often used in conjunction with chemotherapy, as this makes the cancer cells more sensitive to the radiation.

Radiotherapy is used in two circumstances:

  • Before surgery to weaken and shrink the cancer, making it easier to remove. This is referred to as preoperative radiotherapy.
  • After surgery to prevent the cancer from coming back. This is referred to as postoperative radiotherapy.