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Treatment - Bowel cancer

Treatment for bowel cancer will depend on which part of your bowel is affected and how far the cancer has spread.

Surgery is usually the main treatment for bowel cancer, and may be combined with chemotherapy, radiotherapy or biological treatments, depending on your particular case.

If it's detected early enough, treatment can cure bowel cancer and stop it coming back.

Unfortunately, a complete cure isn't always possible and there's sometimes a risk that the cancer could recur at a later stage.

A cure is highly unlikely in more advanced cases that can't be removed completely by surgery.

But symptoms can be controlled and the spread of the cancer can be slowed using a combination of treatments.

Your treatment team

If you're diagnosed with bowel cancer, you'll be cared for by a multidisciplinary team, including:

  • a specialist cancer surgeon
  • a radiotherapy and chemotherapy specialist (an oncologist)
  • a radiologist
  • a specialist nurse

When deciding what treatment is best for you, your care team will consider the type and size of the cancer, your general health, whether the cancer has spread to other parts of your body, and how aggressive the cancer is.

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Surgery for colon cancer

If colon cancer is at a very early stage, it may be possible to remove just a small piece of the lining of the colon wall, known as local excision.

If the cancer spreads into muscles surrounding the colon, it's usually necessary to remove an entire section of your colon, known as a colectomy.

There are 3 ways a colectomy can be performed:

  • an open colectomy – where the surgeon makes a large cut (incision) in your abdomen and removes a section of your colon
  • a laparoscopic (keyhole) colectomy – where the surgeon makes a number of small incisions in your abdomen and uses special instruments guided by a camera to remove a section of colon
  • robotic surgery – a type of keyhole surgery where the surgeon's instruments guide the robot, which removes the cancer

During robotic surgery, there's no direct connection between the surgeon and the patient, which means it would be possible for the surgeon to not be in the same hospital as the patient.

Robotic surgery isn't available in many centres in the UK at the moment.

During surgery, nearby lymph nodes are also removed. It's usual to join the ends of the bowel together after bowel cancer surgery, but very occasionally this isn't possible and a stoma is needed.

Both open and laparoscopic colectomies are thought to be equally effective at removing cancer, and have similar risks of complications.

But laparoscopic or robotic colectomies have the advantage of a faster recovery time and less postoperative pain.

Laparoscopic surgery is now becoming the routine way of doing most of these operations.

Laparoscopic colectomies should be available in all hospitals that carry out bowel cancer surgery, although not all surgeons perform this type of surgery.

Discuss your options with your surgeon to see if this method can be used.

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Surgery for rectal cancer

There are a number of different types of operation that can be carried out to treat rectal cancer, depending on how far the cancer has spread.

Some operations are entirely through the bottom, with no need for abdominal incisions.

Some of the main techniques used are described below.

Local resection

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 (transanal, through the bottom resection).

The surgeon puts an endoscope in through your back passage and removes the cancer from the wall of the rectum.

Total mesenteric excision

In most cases, a local resection isn't possible at the moment. Instead, a larger area of the rectum will need to be removed.

This area will include a border of rectal tissue free of cancer cells, as well as fatty tissue from around the bowel (the mesentery).

This type of operation is known as total mesenteric excision (TME).

Removing the mesentery can help ensure all the cancerous cells are removed, which can lower the risk of the cancer recurring at a later stage.

Depending on where in your rectum the cancer is located, one of two main types of TME operations may be carried out.

These are outlined below.

Anterior resection

Low anterior resection is a procedure used to treat cases where the cancer is away from the sphincters that control bowel action.

The surgeon will make an incision in your abdomen and remove part of your rectum, as well as some surrounding tissue to make sure any lymph glands containing cancer cells are also removed.

They then attach your colon to the lowest part of your rectum or upper part of the anal canal.

Sometimes they turn the end of the colon into an internal pouch to replace the rectum.

You'll probably require a temporary stoma to give the joined section of bowel time to heal.

This will be closed at a second, less major, operation.

Abdominoperineal resection

Abdominoperineal resection is used to treat cases where the cancer is in the lowest section of your rectum.

In this case, it's usually necessary to remove the whole of your rectum and surrounding muscles to reduce the risk of the cancer regrowing in the same area.

This involves removing and closing the anus and removing its sphincter muscles, so there's no option except to have a permanent stoma after the operation.

Bowel cancer surgeons always do their best to avoid giving people permanent stomas wherever possible.

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Stoma surgery

Where a section of the bowel is removed and the remaining bowel joined, the surgeon may sometimes decide to divert your faeces away from the join to allow it to heal.

The faeces are temporarily diverted by bringing a loop of bowel out through the abdominal wall and attaching it to the skin – this is called a stoma. A bag is worn over the stoma to collect the faeces.

When the stoma is made from the small bowel (ileum) it's called an ileostomy, and when it's made from the large bowel (colon) it's called a colostomy

A specialist nurse known as a stoma care nurse can advise you on the best site for a stoma prior to surgery.

The nurse will take into account factors such as your body shape and lifestyle, although this may not be possible where surgery is performed in an emergency.

In the first few days after surgery, the stoma care nurse will advise on the care necessary to look after the stoma and the type of bag suitable.

Once the join in the bowel has safely healed, which can take several weeks, the stoma can be closed during further surgery.

For various reasons, in some people rejoining the bowel may not be possible, or may lead to problems controlling bowel function, and the stoma may become permanent.

Before having surgery, the care team will advise you about whether it may be necessary to form an ileostomy or colostomy, and the likelihood of this being temporary or permanent.

There are patient support groups available that provide support for patients who have just had or are about to have a stoma.

You can get more details from your stoma care nurse, or visit the groups online for further information.

These include:

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Side effects of surgery

Bowel cancer operations carry many of the same risks as other major operations, including:

  • bleeding
  • infection
  • developing blood clots
  • heart or breathing problems

The operations all carry a number of risks specific to the procedure.

One risk is that the joined up section of bowel may not heal properly and leak inside your abdomen. This is usually only a risk in the first few days after the operation.

Another risk is for people having rectal cancer surgery. The nerves that control urination and sexual function are very close to the rectum, and sometimes surgery to remove a rectal cancer can damage these nerves.

After rectal cancer surgery, most people need to go to the toilet to open their bowels more often than before, although this usually settles down within a few months of the operation.

Occasionally, some people – particularly men – have other distressing symptoms, such as pain in the pelvic area and constipation alternating with frequent bowel motions.

Frequent bowel motions can lead to severe soreness around the anal canal.

Support and advice should be offered on how to cope with these symptoms until the bowel adapts to the loss of part of the back passage.


There are several ways radiotherapy can be used to treat bowel cancer:

  • before surgery – to shrink rectal cancers and increase the chances of complete removal
  • instead of surgery – to cure or stop the spread of early-stage rectal cancer, if you can't have surgery
  • as palliative radiotherapy – to control symptoms and slow the spread of cancer in advanced cases

Radiotherapy given before surgery for rectal cancer can be performed in 2 ways:

  • external radiotherapy – where a machine is used to beam high-energy waves at your rectum to kill cancerous cells
  • internal radiotherapy (brachytherapy) – where a tube that releases a small amount of radiation is inserted into your anus and placed next to the cancer to shrink it and kill the cancer cells

External radiotherapy is usually given daily, 5 days a week, with a break at the weekend.

Depending on the size of your tumour, you may need 1 to 5 weeks of treatment. Each session of radiotherapy is short and will only last for 10 to 15 minutes.

Internal radiotherapy may also involve several treatment sessions. If you're also having surgery, this will usually be carried out a few weeks after your radiotherapy course finishes.

Palliative radiotherapy is usually given in short daily sessions, with a course ranging from 2 to 3 days, up to 10 days.

Short-term side effects of radiotherapy can include:

  • feeling sick
  • fatigue
  • diarrhoea
  • burning and irritation of the skin around the rectum and pelvis – this looks and feels like sunburn
  • a frequent need to urinate
  • a burning sensation when passing urine

These side effects should pass once the course of radiotherapy has finished.

Tell your care team if the side effects of treatment become particularly troublesome.

Additional treatments are often available to help you cope with the side effects better.

Long-term side effects of radiotherapy can include:

If you want to have children, it may be possible to store a sample of your sperm or eggs before treatment begins so they can be used in fertility treatments in the future.

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There are 3 ways chemotherapy can be used to treat bowel cancer:

  • before surgery – used in combination with radiotherapy to shrink the tumour
  • after surgery – to reduce the risk of the cancer recurring
  • palliative chemotherapy – to slow the spread of advanced bowel cancer and help control symptoms

Chemotherapy for bowel cancer usually involves taking a combination of medications that kill cancer cells.

They can be given as a tablet (oral chemotherapy), through a drip in your arm (intravenous chemotherapy), or as a combination of both.

Treatment is given in courses (cycles) that are 2 to 3 weeks long each, depending on the stage or grade of your cancer.

A single session of intravenous chemotherapy can last from several hours to several days.

Most people having oral chemotherapy take tablets over the course of 2 weeks before having a break from treatment for another week.

A course of chemotherapy can last up to 6 months, depending on how well you respond to the treatment.

In some cases, it can be given in smaller doses over longer periods of time (maintenance chemotherapy).

Side effects of chemotherapy can include:

  • fatigue
  • feeling sick
  • vomiting
  • diarrhoea
  • mouth ulcers
  • hair loss with certain treatment regimens, but this is generally uncommon in the treatment of bowel cancer       
  • a sensation of numbness, tingling or burning in your hands, feet and neck

These side effects should gradually pass once your treatment has finished.

It usually takes a few months for your hair to grow back if you experience hair loss.

Chemotherapy can also weaken your immune system, making you more vulnerable to infection.

Inform your care team or GP as soon as possible if you experience possible signs of an infection, including a high temperature (fever) or a sudden feeling of being generally unwell.

Medications used in chemotherapy can cause temporary damage to men's sperm and women's eggs.

This means there's a risk to the unborn baby's health for women who become pregnant or men who father a child. 

It's recommended that you use a reliable method of contraception while having chemotherapy treatment and for a period after your treatment has finished.

Biological treatments

Biological treatments, including cetuximab and panitumumab, are newer medicines also known as monoclonal antibodies.

They target special proteins, called epidermal growth factor receptors (EGFRs), found on the surface of some cancer cells.

As EGFRs help the cancer grow, targeting these proteins can help shrink tumours and improve the effect of chemotherapy.

Biological treatments are sometimes used in combination with chemotherapy when the cancer has spread beyond the bowel (metastatic bowel cancer).

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Page last reviewed: 6 October 2016
Next review due: 6 October 2019