Once your doctor has received the results of the tests and fully understands the extent of the cancer, he / she will be able to discuss your diagnosis and what your treatment options are.


It is most likely that you will be told that you need an operation to remove the tumour. Your doctor may advise that you need surgery before you have any other treatment; alternatively they may advise that you will need chemotherapy and/or radiotherapy to reduce the size of the tumour before surgery.


There are different methods of surgically removing a cancerous tumour from the bowel, depending on the exact location of the cancer, its size and type, and whether the cancer has spread. Your test results will affect the decision on the type of surgery that will be best for you. See also Types of Bowel Surgery.

Surgery for cancer in the colon (the upper part of the large bowel)

The exact location of the cancer in the colon will affect which type of surgery you will need. Ask your doctor to explain what type of operation you are having, and whether they can draw you a diagram that you can take away with you, to make it easier for you to understand where they will be operating.


During the operation, the surgeon will remove the cancerous tumour and a small, healthy area around the tumour called the ‘tumour margin’. This is to ensure that all of the cancerous cells have been removed and none are left behind. The surgery can either be done via the traditional open surgery method or via a technique called laparoscopic (keyhole) surgery.


After the part of the colon containing the tumour is removed, the ends of the colon will be joined back together. The place where they join is called an anastomosis. In some circumstances your surgeon may want to create a stoma to allow the anastomosis to heal, although this is much more common in rectal surgery (see below). This is usually temporary but occasionally permanent. See more information on stomas or download our ‘Stoma Reversal’ factsheet.


The surgeon will also remove nearby lymph nodes. Following the operation these will be examined in the laboratory to see if the cancer has spread. If it has, your specialist team will discuss the proposed course of action with you.

Surgery for cancer in the rectum (the lower part of the large bowel)

Several surgical methods are used for removing rectal cancers and again, this depends on the exact location, its size, type and how advanced the cancer is.


For rectal cancer, chemotherapy and radiotherapy (collectively called chemo-radiation) may be given as a standard treatment, either before or after surgery. The aim is to reduce the size of the tumour before the operation, and minimise the risk of the cancer coming back again afterwards.

Types of rectal surgery

If the tumour in your rectum is still very small, at an early stage and low down in the rectum, your surgeon may choose to remove the tumour via a technique called local transanal resection. The tumour can be removed with instruments inserted through your anus (back passage) without the need for making a surgical incision in your abdomen.


Another new technique, the APPEAR technique, can be used for very low rectal cancers, as part of a planned endoscopic surgery. Here, two specially trained surgeons work together to remove the tumour without having to remove or damage the muscle of the anus, with a lower risk of needing a permanent stoma.


TEMS (transanal endoscopic microsurgery) can be suitable for small, very early cancers (T1 and T2 tumours) high up in the rectum and is a minimally invasive technique. The surgeon inserts a specially designed sigmoidoscope into your anus to remove the tumour from the wall of the rectum, using specialist forceps and diathermy (to seal the blood vessels). This technique is not available in every hospital, however you can request to be referred to a specialist centre if your multidisciplinary team feels that you might be a suitable candidate.


There are, however, occasions when it is necessary to perform an operation via an incision in your abdomen.

Total mesorectal excision (TME)

The ‘gold standard’ open surgery technique for rectal cancer is a total mesorectal excision (TME). This procedure involves the careful removal of the whole of the rectum as well as the fatty tissue around the rectum (which contains the lymph nodes). Research has shown that TME is more effective than other types of surgery at reducing the risk of the cancer coming back.


Depending upon the position of the tumour in the rectum, its size, and how far it is from the anal sphincter (the muscle which keeps the anus closed and prevents stool leakage), your surgeon will perform the operation using the TME technique in the following way:


  • Low anterior resection: The surgeon removes the tumour without affecting the anus; your colon will be attached to the remaining part of the rectum and you will be able to continue to move your bowels in the usual way after surgery, although a temporary stoma may be formed for a short period (for approx 8 weeks) to allow the bowel to heal.
  • Colo-anal ‘J pouch’ surgery: The surgeon removes the rectum and attaches the colon directly to the anus. It is sometimes possible for the surgeon to make a ‘new’ rectum from a short section of the colon, which will work like the rectum did before surgery. During this operation you may have a temporary stoma formed (for approx 8 weeks) to allow the bowel to heal.
  • Abdominoperineal (AP) resection: An operation used to treat cancers in the lower third of the rectum (the nearest part to the anus). This operation involves removing the affected part of the rectum, the anal sphincter muscles and the anus. A permanent stoma will need to be formed to allow the stools to exit the body.


Download our booklet ‘Bowel Cancer Surgery – Your Operation’.


Louisa, our nurse, answers your question “I have just had bowel cancer surgery and I’m still bleeding from my bottom. Is this normal?

Emergency surgery

Whilst many patients have time to plan for their surgery, some patients are diagnosed with bowel cancer following emergency admission to hospital with abdominal pain or other severe symptoms. In these cases, it can be difficult for the doctor to diagnose bowel cancer without undertaking exploratory surgery.


In cases where patients are admitted as an emergency, with a blockage in the bowel caused by a tumour, the surgeon may choose to insert a colonic stent as a temporary way of unblocking the bowel before extensive surgery can be planned. Download our ‘Colonic Stenting’ factsheet.