Bowel cancer surgery: when it is needed and what is involved

Bowel cancer is one of the most common cancers worldwide and affects around one in 20 women and one in 17 men in the UK. It refers to cancer that starts in the colon or rectum and usually develops from polyps, that is, non-cancerous growths that if left for long enough can become cancerous. 

Bowel cancer is usually diagnosed via a colonoscopy, where a thin, flexible telescope-like camera with a light on the end is passed through your back passage (rectum) and into your colon. This allows your doctor to look for abnormal growths and if needed, collect a tissue sample (biopsy) for examination in a laboratory. 

Treatment options for bowel cancer vary depending on the type and stage of bowel cancer but often involve a combination of surgery with or without chemotherapy, and may also involve radiotherapy and/or immunotherapy.

When is bowel cancer surgery needed?

Bowel cancer surgery may be recommended for different stages of bowel cancer. 

In early-stage bowel cancer, it may be performed to remove the area of the bowel containing the tumour (bowel resection), including the surrounding blood supply to the tumour and nearby lymph nodes. In most cases, this could be curative.

For more advanced stages of bowel cancer, surgery may be performed to remove the bowel, nearby lymph nodes and adjacent organs if necessary. More advanced bowel cancers are more likely to require additional treatment with chemotherapy and/or radiotherapy.

In cases where the cancer is not curable, surgery may still be performed to help control symptoms and improve quality of life. 

How bowel cancer surgery is performed 

Most bowel cancer surgery is performed via keyhole techniques. This involves making small cuts on the abdomen, through which special surgical instruments are passed alongside a thin telescope camera with a light on the end.  Some operations may need open surgery where a larger cut is made in the abdomen to allow the surgeon more direct access.

Keyhole surgery can be performed laparoscopically with the instruments being held by the surgeon or robotically using a robotic device to hold the instruments that is directly controlled by the surgeon. 

The advantages of keyhole surgery compared with open surgery are due to smaller cuts, less pain, less blood loss and a quicker recovery. This leads to a shorter hospital stay and fewer long-term risks such as hernia formation. 

Whichever type of bowel cancer surgery you have, the duration of your surgery will depend on its complexity. On average, bowel cancer surgery takes two to four hours. 

Your stay in hospital will also depend on the complexity of your surgery, as well as the type of surgery performed (keyhole versus open). You may be in hospital for as little as 48 hours or as long as 14 days. However, typical bowel cancer surgery requires a hospital stay of five to seven days. 

Preparing for surgery

How you prepare for surgery will depend on the type and complexity of surgery you have. It is important to attend your pre-operative assessment and stay in close contact with your care team. This will involve a period of fasting and possibly bowel preparation ahead of surgery. 

The better health you are in before your surgery, the lower the risk of complications. It, therefore, helps to quit smoking and reduce your alcohol intake. 

Your care team may also advise you on prehabilitation, that is, exercises you can perform to stay fit prior to surgery. Both your heart and lungs will be put under stress during your surgery, despite you being under general anaesthesia. Improving your fitness can, therefore, reduce the risk of complications during surgery and aid your recovery. 

Outcomes for bowel cancer surgery

The success of your surgery in treating your bower cancer will depend on the type and stage of bowel cancer you have, as well as your general health before surgery. 

In earlier stages of bowel cancer, removal of the entire bowel and nearby lymph nodes offers a five-year survival rate of around 90%. The more advanced the cancer is, the lower the five-year survival rate after surgery. 

Complications of bowel cancer surgery

Every surgery comes with the risk of bleeding, infection, scarring, tissue damage and the risks of general anaesthesia, which include an allergic reaction, blood clots in the legs and lungs, heart attack and stroke. 

Risks specific to bowel cancer surgery include damage to other parts of the bowel, spleen and/or ureter. If only part of the bowel is removed and the two open ends reconnected, there is a risk of leakage from the bowel (anastomotic leak). 

Symptoms of an anastomotic leak include severe abdominal pain, fever, vomiting and feeling very unwell. This is a serious condition that needs emergency surgery to repair the leak and repair, in some cases, the formation of a stoma (an opening to the surface of your body). 

Life after bowel cancer surgery

If your bowel cancer surgery involves removing only a part of your bowel, there are usually no long-term changes to your bowel function. 

However, in some cases, you may find that your stools are looser. This is because your colon allows fluid to be absorbed from your stools into your body; a shorter colon, therefore, may reduce the amount of fluid absorbed from your stools. 

If the left-hand section of your colon and/or rectum is removed, you may find that you need to open your bowels more often and that when you do so, you still don’t feel as if you have emptied your bowels fully. 

Sometimes bowel surgery requires the bowel to be brought to the surface of the abdomen and, through an opening made into the abdomen (a stoma), connected to a bag to collect the stools. This is called an ileostomy and after this procedure, you will no longer be able to go to the toilet in the usual way with your stools passing out of your rectum. Stomas can either be permanent or temporary. 

If you need an ileostomy, a special nurse called a stoma nurse will explain how to take care of your ileostomy and provide advice on how to adjust to living with an ileostomy.