Beating bowel cancer together

Types of surgery

The type of surgery you have will depend on where your cancer is, what size it is and whether it has spread to other parts of the body. If your cancer has spread outside the colon or rectum, read our information on treatments for advanced cancer.

This page describes local resection, surgery for colon cancer, surgery for rectal cancer, open and keyhole surgery, and surgery for a blocked bowel.


Local resection

If you have a very small, early stage cancer, the surgeon may remove it from the lining of the bowel in an operation called local resection.

The doctor uses a flexible tube with a light at the end (a colonoscope or sigmoidoscope) to remove the cancer from the colon or rectum. They also take away some of the tissue from around the cancer to make sure no cancer cells are left behind.

A doctor, called a pathologist, will look at the cancer cells under the microscope to see how normal or abnormal they look. This is called grading the cancer. If the cancer cells look very abnormal and your cancer specialist thinks the cancer may have spread into the lining of the colon or rectum or to the lymph nodes, you may need a larger operation to remove more tissue. 

Surgery for colon cancer 

The surgeon will remove the part of the colon that contains the cancer and the nearby lymph nodes. This is called a colectomy.

The most common types of surgery are described here. Your healthcare team can give you more information about the type of surgery you will have or have had.

If the cancer is in the right side of the colon, you will have a right hemi-colectomy. If the cancer is in the middle section of the colon, most surgeons will extend a right hemi-colectomy into the middle section of colon to remove the cancer (extended right hemicolectomy).

If the cancer is in the left side of the colon, you will have a left hemi-colectomy. Depending on where exactly the cancer is, the operation will remove a variable amount of the colon and lymph nodes.

sub-total colectomy removes the whole colon, leaving the rectum in place. A procto-colectomy removes the colon and the rectum and a pan procto-colectomy removes the colon, rectum and anus. These operations aren’t common and are usually only offered to people who have more than one cancer in their bowel or who have a genetic condition called FAP

Once the cancer has been removed, the surgeon will join the remaining ends of bowel together using stitches or staples if possible. This join is called an anastomosis.

Some people need to have a stoma. This is where a section of bowel is brought out through an opening on your stomach area (abdomen). This part of the bowel then empties into a bag which is stuck onto your skin (stoma bag). This then involves you regularly emptying or changing this bag. You may have a temporary stoma to let your bowel rest after surgery. Some people may need a permanent stoma, for example if the remaining ends of bowel can’t be joined together.

After the operation, your surgeon will have more information about the size and spread (stage) of your cancer. A doctor, called a pathologist, will look at the cancer cells under a microscope to see how normal or abnormal they look. This is called grading the cancer. You may have chemotherapy after your surgery if the cancer has spread to the lymph nodes or there is a high risk of it spreading to other parts of the body.

Surgery for rectal cancer

If you have a small, very early rectal cancer or if you can't have major surgery, your surgeon may offer you a local resection. This is called transanal endoscopic mircosurgery (TEMS) or transanal minimally invasive surgery (TAMIS).

The surgeon passes the surgical instruments through the back passage (anus) so you will not have any cuts in your stomach area (abdomen). The surgeon uses the instruments to remove the cancer and the surrounding healthy tissue, to make sure that no cancer cells are left behind. If the surgeon can't remove the cancer this way, they may need to switch to a larger operation. If there is a chance of this happening, your surgeon will tell you before your operation. 

If you have a stage 3 or stage 4 cancer, your healthcare team may offer you other treatments before your surgery. You may have a short course of radiotherapy or you may have radiotherapy together with chemotherapy (chemoradiation). These treatments shrink the cancer, making it easier to remove, and reduce the risk of it coming back. In some cases, these treatments shrink the cancer so that it cannot be felt anymore. If this is the case your doctor will talk to you about whether you would like to have the area removed or regular checking of the area.

If the cancer is in the rectum or the sigmoid colon, you will probably be offered an anterior resection. In this operation part, or all, of the rectum or sigmoid colon is removed together with all the surrounding fatty tissue and the sheet of tissue that contains lymph nodes and blood vessels (mesorectum). This reduces the risk of the cancer coming back. This technique is called total mesorectal excision (TME). TME is the gold standard (best) treatment for cancers in the rectum and is performed by all surgeons in the UK.

Depending on how much rectum your surgeon has removed, you may need to have a stoma for a few months after the operation to let the bowel heal.

For cancers in the lower part of the rectum, the surgeon will remove most of the rectum. They will join the end of the colon to the anus. This join is called a colo-anal anastomosis. Sometimes the surgeon uses the end of the colon to make a pouch, called a J pouch (colo-anal J pouch surgery) This acts like the rectum to store bowel movements before you go to the toilet. You may need to have a stoma while your bowel heals. In most cases, the stoma can be reversed after a few months.

If the cancer is very low down in the rectum, your surgeon will need to remove the rectum and anus. This operation is called abdomino-perineal resection of the rectum (APeR). This operation involves removing the whole of your rectum and anal canal. Your anus will be removed and the skin in this area will be closed. This means that you will have a permanent stoma.

There are different ways you can have surgery

Your surgeon may offer you a choice of open, keyhole (laparoscopic) surgery or robotic-assisted surgery. The way your operation is carried out will depend on lots of factors, including where your cancer is, whether it has spread to other parts of the body and your general health.

Your healthcare team will offer the best and safest option for you. Speak to your healthcare team if you have any questions about your surgery.

Open surgery

In open surgery, the surgeon will make one opening in the stomach area (abdomen) to remove the cancer.

Your surgeon may recommend open surgery if:

  • the tumour is large or difficult to access
  • you have had abdominal surgery before
  • you're very overweight


Compared with keyhole surgery, the advantages of open surgery include:

  • the surgeon directly seeing and feeling what they're doing, which may make the operation less challenging
  • a shorter operation time


Compared with keyhole surgery, the disadvantages of open surgery include:

  • a larger wound that takes longer to heal
  • a higher chance of a wound infection and part of the bowel pushing through the wound (hernia)
  • a longer hospital stay
  • a longer recovery time

Keyhole (laparoscopic) surgery

If your operation is planned, your surgeon is likely to offer you keyhole surgery. This is sometimes called laparoscopic surgery or minimally invasive surgery.

Keyhole surgery involves making a few small openings in the stomach area (abdominal wall) to remove the cancer. The surgeon passes special instruments and a thin tube with a light and camera on the end (called a laparoscope) through the small openings to remove the tumour. This is sometimes called laparoscopic surgery.

Some specialist centres offer Single Incision Laparoscopic Surgery (SILS), which involves making one small cut in the abdomen. SILS is a new type of surgery, but it has similar results to standard keyhole surgery.


Compared with open surgery, the advantages of keyhole surgery include:

  • less pain after surgery
  • lower chance of complications, such as infection, after surgery
  • lower chance of needing a blood transfusion
  • a shorter hospital stay
  • faster recovery


Compared with open surgery, the disadvantages of keyhole surgery include:

  • not being suitable for all rectal cancers
  • a longer operation than open surgery
  • not being suitable if you are very overweight, if you have had abdominal surgery before or if the tumour is large
  • the surgeon may need to switch to open surgery during the operation

Robotic-assisted surgery

Robotic-assisted surgery is when the surgeon uses a surgical robotic system to operate on the cancer. The surgeon makes a few small openings in the stomach area (abdomen) and passes instruments through them to remove the tumour.

It's important to understand that the robotic system doesn't perform your procedure. Your surgeon will be carrying out the operation alongside their team and will be in control of your operation the whole time.

The robotic system has four arms that hold a camera and the surgical tools. A surgeon controls the robotic system from the surgeon console, which is in the operating theatre. Their team helps with the operation.

Sometimes during robotic-assisted surgery, the surgeon may need to switch to open surgery during the operation. Your surgeon will discuss this with you before your operation.

Robotic-assisted surgery isn't available in all hospitals in the UK yet but it's becoming more common. Not everyone can have robotic-assisted surgery. Your healthcare team will discuss with you which surgery is best for you.

Research is ongoing to fully understand the benefits of robotic-assisted surgery compared to open and keyhole surgery.

You can find out more about robotic-assisted surgery in our factsheet or our video below.

Surgery for a blocked bowel

Sometimes cancer can block the bowel, stopping bowel movements from passing through. This is called bowel obstruction. It can cause pain, bloating and vomiting (being sick). If this happens you will need to have an operation as soon as possible.

The surgeon may unblock your bowel by putting in a hollow, expandable tube called a stent. This holds the bowel open so that bowel movements can pass through. The stent stays inside your bowel. You may have another operation later on to remove the cancer.

Another option is for the surgeon to remove the part of the bowel that is blocked. You may need a temporary or permanent stoma afterwards.

If re-joining the bowel is too risky and the blockage or damage is in the left side of the bowel, your surgeon may remove the sigmoid colon and the top part of the rectum. This is called Hartmann’s procedure. You will have a stoma, which is usually permanent but in some cases can be reversed. Your rectum and anus will still be in place.

If the surgeon isn’t able to remove the blockage, you may have a temporary stoma until you are able to have further treatment.

More information


Updated August 2018


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