Help us to stop bowel cancer

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 surgeon 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 left side of the colon, you will have an operation called a left hemi-colectomy.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, some surgeons may extend a right hemi-colectomy into the middle section of colon to remove the cancer.

If the cancer is in the last part of the colon (sigmoid colon), you will have a sigmoid colectomy.

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). 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 cancer or if you can't have major surgery, your surgeon may offer you a local resection. This is called transanal endoscopic mircosurgery (TEM). 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.

Surgery involves taking away the part of the rectum where the cancer is, 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 operation is called total mesorectal excision (TME). TME is the gold standard treatment for cancers in the middle or lower section of the rectum.

If the cancer is high up in the rectum, your surgeon may only remove part of the mesorectum to avoid damaging the bowel. This operation is called an anterior resection. The surgeon joins the end of the colon to the part of the rectum that is left. 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 excision of the rectum (APeR). Your anus will be closed and you will have a permanent stoma.

Open and keyhole surgery

Your surgeon may offer you a choice of open surgery or keyhole (laparoscopic) surgery. You may not be able to have keyhole surgery if you are very overweight, if you have had surgery to the stomach area (abdomen) before or if you have advanced disease.

In open surgery, the surgeon will make one opening from just below your breastbone down to just above your pubic bone. In keyhole surgery, you will have three or four small openings in your stomach area (abdomen). The surgeon puts a long, thin tube with a light and camera (laparoscope) through one of the openings. This lets the surgeon see inside your abdomen. They pass surgical instruments through the other openings to remove the cancer.

Both types of surgery have similar results when they are done by an experienced surgeon. The keyhole operation usually takes longer but you may recover more quickly. Sometimes the surgeon will need to switch from keyhole to open surgery during the operation. Speak to your surgeon about the risks and benefits of both types of surgery and which option is best for you.

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 straight away.

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

Cancer Research UK has more information on bowel cancer surgery.

Macmillan Cancer Support has more information on surgery for colon cancer and rectal cancer.

Association of Coloproctology of Great Britain and Ireland provides information on bowel cancer surgery.


Updated March 2016. Due for review March 2019