Types of surgery for bowel cancer

The type of operation you have will depend on

• Where the cancer is in the bowel
• The type and size of the cancer
• Whether the cancer has spread

Before your operation your doctor will talk to you about the best type of surgery for you.

Remember that a surgeon will not carry out any operation without your consent. Your surgeon will answer your questions about the choice of operation before you sign the consent form.

The main types of operation for bowel cancer are outlined below.

If you have a very small, early stage, cancer of the large bowel or back passage, your surgeon may just remove the cancer from the bowel lining. This operation is called a local resection. The surgeon will also remove a border of healthy tissue from around the cancer that contains no cancer cells. This is to try and make sure no cancer cells were left behind.

Your surgeon sends the tissue they've removed to the laboratory. A pathologist looks at the cells under a microscope to see how abnormal they are. This tells your doctor the grade of the cancer. If the cells look very abnormal (high grade) your surgeon may decide you need a second, larger operation. The second operation is to remove more tissue that could contain cancer cells and lower the chance of the cancer coming back.

The type of operation you have depends on where the tumour is in your large bowel (colon). The surgeon makes a cut in your abdomen to remove the part of the colon containing the tumour. This operation is called a colectomy. How much your surgeon takes away depends on the exact position and size of the cancer. Your surgeon will remove the lymph glands closest to the bowel, in case any cancer cells have spread there.

If the left side of the colon is removed, the operation is called a left hemi colectomy.

If the middle part of the bowel is removed (the transverse colon) it is called a transverse colectomy.

If the right side of the colon is removed, it is called a right hemi colectomy.

If the sigmoid colon is removed it is called a sigmoid colectomy.

After your surgeon removes part of the bowel with the tumour, they join the ends of the colon back together. The join is called an anastomosis. Sometimes, to give the area time to heal, the surgeon makes a temporary colostomy or ileostomy higher up the bowel. You have the temporary stoma repaired in another operation a few months later, called a stoma reversal. In the meantime, you wear a colostomy bag over the opening of the bowel, to collect your bowel motions. We have detailed information about stomas on our pages about having a colostomy and having an ileostomy.

If you have a large amount of colon removed, your surgeon may not be able to join the ends of bowel that are left. You may need to have a permanent colostomy. Your surgeon will avoid this if at all possible. You will be able to ask questions about why you need a colostomy before you sign the consent form. Sometimes surgeons can't tell whether you will need a permanent colostomy until during the operation. They may not know how big the tumour is, or how much of the bowel it affects. Your surgeon will explain this to you before the operation.

Surgery to remove the whole colon is called a total colectomy. The surgeon makes a cut in the abdomen to remove the colon. They bring the upper end of the bowel out onto the surface of the abdomen to make a colostomy or ileostomy.

After these operations, you usually have a wound from the bottom of your breast bone (sternum) down to the level of your hip bones (your pelvis). Some people may have keyhole surgery for colon cancer instead of the open surgery described here.

You may have radiotherapy or chemoradiotherapy to shrink the cancer before surgery and make it easier to remove. This also lowers the chance of the cancer coming back in the back passage after surgery.

If you have a very small, early stage rectal cancer, your surgeon may be able to remove it in an operation called a local resection (trans anal resection). The surgeon puts an endoscope (a flexible tube with a light) in through your back passage and removes the cancer from the wall of the rectum. Surgeons call this operation trans anal endoscopic microsurgery (TEM).

During most operations for rectal cancer, the surgeon removes the cancer with a border of rectal tissue around it that is free of cancer cells. They call this border of tissue a 'clear margin'.  They also remove fatty tissue from around the bowel and a sheet of body tissue called the mesentery (pronounced meez-ent-air-ee). This sheet of tissue surrounds the intestine, bowel and rectum. It contains all the blood vessels that supply the rectum and the lymph nodes that carry tissue fluid away from it. So any lymph nodes that contain cancer cells are likely to be in the mesentery. Small groups of cancer cells may also spread into the mesentery. 

Taking the mesentery away completely, along with a border of tissue immediately around the cancer, lowers the risk of the cancer coming back.  This type of operation is known as total mesenteric excision or TME. With TME surgery it is possible to get margins that are free of cancer cells in 9 out of 10 operations for rectal cancer.

For cancers higher up in the back passage, your surgeon will remove the part of the rectum containing the tumour. This is called a low anterior resection. The surgeon makes a cut in the abdomen and removes the cancer with a border of normal tissue on either side of it. The surgeon attaches the end of the colon to the remaining part of the rectum.  They will also remove the mesentery down to 5 cm below the bottom edge of the tumour. They do not remove the whole mesentery because then there is a greater risk of having a leaking bowel after surgery.

If your tumour is in the middle part of your back passage, your surgeon may remove most of the rectum and attach the colon to the anus (the opening of the bowel to the outside of the body). This is called a colo anal anastomosis. Sometimes the surgeon can make a small pouch by folding back a short section of colon or by enlarging a section of colon. This small pouch then works like the rectum did before surgery.

During this operation you may have a temporary colostomy made. You have this for about 8 weeks while the bowel heals. You then have a second operation to close the colostomy opening. Closing the colostomy is also called stoma reversal. Sometimes, with a colo anal anastomosis you may need to have a permanent colostomy instead of a temporary one.

If the cancer is in the lower part of your rectum, your surgeon will not be able to leave enough of the rectum behind for it to work properly. So, the surgeon removes your anus and rectum completely. This is called an abdominoperineal resection (AP resection for short). Then the surgeon makes a permanent colostomy opening on your abdomen. After this type of surgery you have 2 wounds – a wound on your abdomen and a second wound where your anus has been closed.

Surgeons may use keyhole surgery to remove early stage bowel tumours. This type of operation is also called a laparoscopic resection. The surgeon makes several cuts in your tummy (abdomen), each smaller than 1.5cm, instead of making one large cut as you'd have with open surgery. The surgeon passes a long, narrow tube called a laparoscope, and other instruments, through the cuts. The laparoscope has a light on the end so the surgeon can look into your abdomen. They remove the tumour through as small a cut as possible. This type of surgery usually takes about 40 minutes longer than a traditional open operation.

Keyhole surgery seems to be as good as traditional open operations at getting rid of the cancer. We know from research that people who have this type of surgery may have less pain and get back to normal more quickly. You may also leave hospital sooner. In August 2006 the National Institute for Health and Clinical Excellence (NICE) approved laparoscopic bowel surgery as a possible alternative to traditional open surgery for people with bowel cancer. But your doctor should talk to you beforehand about the risks and benefits of both types of surgery. Surgeons must have additional specialist training to perform this operation. The NHS aims to offer laparoscopic surgery in all hospitals by 2012.

Usually surgery for bowel cancer is planned in advance, after tests have found the cancer. But sometimes the cancer completely blocks the bowel at the time it is found. This is called bowel obstruction. In this situation you need an operation straight away. The surgeon may put a tube called a stent into the bowel during an endoscopy. The stent holds the bowel open so that it can work normally again. Or you may have immediate surgery to remove the tumour from the bowel. There is information about this type of operation in the surgery for bowel obstruction section.