Bowel cancer

Expert reviewer, Mr Stephen Pollard, Consultant Surgeon
Next review due May 2021

Bowel cancer is the name for any cancer that starts in your large bowel. Other names for bowel cancer include colon cancer, rectal cancer and colorectal cancer.

It’s one of the most common types of cancer in the UK; more than 40,000 people get bowel cancer each year.

About bowel cancer

Your large bowel is made up of your colon and your rectum. The colon is further divided into the ascending colon, the transverse colon, the descending colon and the sigmoid colon. Bowel cancer (colorectal cancer) is the name for a cancer that affects your large bowel and so can be divided into colon cancer, or rectal cancer.

Around seven in 10 bowel cancers start in the colon; three in 10 start in the rectum. Usually, bowel cancer develops from small, non-cancerous (benign) growths of tissue called polyps that can develop here. If these polyps aren’t removed, they can sometimes become cancerous (malignant) over time.

Bowel cancer can spread through the wall of your bowel to the surrounding tissues, and to the lymph nodes nearby. It can also spread via your bloodstream to your liver and your lungs. The earlier bowel cancer is diagnosed, the better your chance of a cure. That’s why it’s so important to have cancer screening if it’s offered and to see your GP if you have symptoms of bowel cancer.

It’s rare to get bowel cancer if you’re under 40. Nearly three-quarters of people who get bowel cancer are 65 or over.

Image showing the large and small bowels

Symptoms of bowel cancer

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Having these symptoms doesn’t necessarily mean that you have bowel cancer. But if you have them, especially if they’re persistent and not normal for you, contact your GP. You should always contact your GP if you have blood in your poo.

Diagnosis of bowel cancer

Your GP will ask about your symptoms and examine you, and they may ask you about your medical history. Your GP may need to examine your rectum (back passage). They’ll do this by inserting a finger into your rectum to feel for any lumps or swellings. See our question below about ‘what happens during a rectal examination’.

Your GP may ask you to have a blood test to see if you have anaemia and to check your general health.

If you haven’t noticed blood in your poo yourself, your GP may recommend a test to see if there’s any ‘hidden’ blood in your poo. You’ll need to provide a sample of your poo for this – your GP will explain exactly what you need to do.

If your GP thinks you might have bowel cancer, they’ll refer you to a doctor or surgeon who specialises in diseases of the large bowel.

Tests for bowel cancer include the following.

  • A colonoscopy is a test that allows your doctor to look inside your large bowel. They’ll use a narrow, flexible, tube-like telescopic camera called a colonoscope to do this. Your doctor may need to take a biopsy (small sample of tissue), which they’ll send to a lab to look for cancer cells. If you have polyps which might turn into cancer, your doctor may remove these at this time.
  • A sigmoidoscopy is a procedure to look inside your rectum and the lower part of your bowel.
  • A barium enema involves putting a fluid that contains barium (a substance that shows up on X-rays) into your bowel via your rectum. X-ray images of your abdomen then show the inside of your bowel more clearly.
  • A virtual colonoscopy uses a CT scan to create a three-dimensional image of the inside of your bowel. This is an option if you aren’t well enough to have a colonoscopy. It’s also known as CT colonography.

If these tests find you have bowel cancer, you’ll need further tests to find the size and position of the cancer. These tests will also check to see whether or not it has spread beyond the bowel. This is called staging.

These tests may include:

  • an ultrasound scan of your abdomen (tummy) to see if the cancer has spread to your liver
  • a CT scan to show where the cancer is and whether it has spread
  • an MRI scan to give detailed pictures of your rectum if the cancer is lower down in your bowel
  • further blood tests to check your general health

If your doctor recommends any of these tests, they’ll explain exactly what’s involved and how the test may help. If you have any questions about your tests, feel free to ask your doctor. You can find out more about these tests by following the links in our text above. You’ll also find more information about cancer tests from the organisations we list below in our section ‘other helpful websites’.

Screening for bowel cancer

Screening is important as it may detect bowel cancer in its early stages before you have symptoms. If bowel cancer is found early, there’s more chance that it can be cured.

There are different bowel cancer screening programmes running in different parts of the UK.

  • In England, Wales and Northern Ireland, if you're between 60 and 74, you’ll be sent a bowel cancer screening kit. You can also request a kit if you're over 74.
  • In Scotland, you’ll get a kit through the post if you’re between 50 and 74. You can also request a kit if you’re over 74.

The screening kit contains a faecal occult blood (FOB) test that can detect small amounts of blood in your poo. (‘Occult’ just means hidden.) The FOB test doesn't diagnose bowel cancer – the results show if you need to have your bowel examined. Even if you have a screening test with a normal result, if you have symptoms, you should still see your doctor.

The Department of Health is also rolling out a bowel scope screening programme in some parts of England. If you live in one of these areas, you’ll be invited to have a sigmoidoscopy test around your 55th birthday. You’ll still be sent a bowel cancer screening kit after you're 60.

Your GP surgery will have information about the screening programme in your area.

Screening for people at risk of bowel cancer

If you have a higher risk of getting bowel cancer than most people, you may have more regular tests to check for bowel cancer. This could be because you have a close relative who’s had bowel cancer, you’ve had bowel polyps or a health condition (such as long-standing colitis) puts you at risk. See our section below on causes of bowel cancer, and our question about people with other bowel conditions.

If you think you may have an increased risk of getting bowel cancer, ask your GP about screening.

Treatment of bowel cancer

A team of doctors and other cancer specialists will discuss the best treatment to offer you in your particular circumstances. The type of treatment they recommend will depend on the size of your cancer, its position and whether it has spread.

You may have treatment to:

  • cure bowel cancer
  • shrink or slow down the growth of bowel cancer to prolong your life
  • reduce the symptoms caused by bowel cancer – this is called palliative therapy

It’s possible you could be cured with surgery and medicines if you find out you have bowel cancer early on. If you’re diagnosed later and the cancer has spread, this might not be possible. But treatments may still help to prolong your life and help with symptoms.


Surgery is the most common treatment for bowel cancer. You can have open surgery, in which your surgeon will make one large cut in your abdomen. Or you may be able to have keyhole surgery (laparoscopic surgery).

If you have cancer in your colon, your surgeon will remove the part that’s affected and if possible join the two open ends together. They may also remove some of your lymph nodes that are close by. Lymph nodes are glands throughout your body that are part of your immune system. They’re often the first place the cancer spreads to.

Your surgeon may decide it’s best to rest your bowel and give it a better chance to heal by forming a stoma. This is where they bring the end of your bowel out to the surface of your abdomen (tummy). This diverts the flow of waste away from your bowel out to be collected in a bag. If it's your large bowel, this is called a colostomy and if it's your small bowel, it's called an ileostomy. This is usually temporary and is reversed a few months later. However, sometimes a permanent stoma is necessary. See our question below on having a colostomy after bowel surgery for cancer.

If you have cancer in your rectum (back passage), your surgeon will remove the cancer and the surrounding tissue. They may also remove some of your lymph nodes. Depending on how much of your rectum your surgeon needs to remove, you may need to have a colostomy.

Have a look at our information on bowel surgery to find out what’s involved in these procedures.

Non-surgical treatments

Chemotherapy and radiotherapy

Your doctor may recommend you have treatment with chemotherapy and/or radiotherapy as well as surgery.

Chemotherapy and radiotherapy aim to destroy any remaining cancer cells, so reducing the chance that the cancer will come back. They are sometimes used to shrink the tumour before surgery. They may also help to reduce your symptoms.

Biological therapies

Biological (targeted) therapies are medicines that can seek out cancer cells and interfere with the way they grow. Biological therapies used to treat bowel cancer include:

  • cetuximab
  • panitumumab
  • bevacizumab

They’re sometimes used alongside chemotherapy for bowel cancer, especially if the cancer has spread to other parts of your body.

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After your treatment

You’ll be asked to attend hospital appointments and have regular check-ups after your treatment. How often these happen will depend upon what stage of cancer and what treatment you had.

Your doctor or nurse will examine you and ask how you are. They may ask you to have some tests at some of your visits. These might include:

It’s important to go along to any appointments you’re offered. These let your doctor see if you’re having any problems after your treatment and to check that the cancer isn’t returning. They also give you the chance to talk about any concerns you have.

Causes of bowel cancer

Doctors don’t completely understand why some people get bowel cancer. It probably happens because of a mixture of different factors.

You’re more likely to get bowel cancer as you get older, with nearly three-quarters of cases being in people aged 65 and over. We also know that your risk of bowel cancer is higher if you:

  • have a family history of bowel cancer – you’re twice as likely to get it if your brother, sister or one of your parents has it
  • have an inherited bowel condition, such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (HNPCC), also known as Lynch syndrome
  • have a long-term bowel condition, such as Crohn's disease or ulcerative colitis
  • have a diet that’s low in fibre, fruit and vegetables and high in processed and red meats
  • don’t do much exercise
  • are obese
  • have diabetes
  • smoke
  • drink a lot of alcohol

Prevention of bowel cancer

You can see by reading the list of causes above that there’s probably a lot you can do to help keep your risk of bowel cancer as low as possible. And the good news is that these are all things which will help to improve your health in many other ways too.

Follow the links we’ve given for lots of helpful advice about how to make these changes. You can get many more tips and hints on living a healthy lifestyle from our health blog.

Help and support

Being diagnosed with bowel cancer and facing treatment can be distressing for you and your family. An important part of cancer treatment is having support to deal with the emotional aspects as well as the physical symptoms. Specialist cancer doctors and nurses are experts in providing the support you need. Talk to your doctor or nurse if you’re finding your feelings hard to cope with.

Everyone has their own way of coping. But for further support and advice you may find it helpful to contact one of the well-known cancer organisations or visit their websites. They have information about most types of cancer – often in more detail than we can go into here. Some have a telephone helpline you can ring, or an online forum you can join for a chat with others in your position. There may also be local groups where you can meet other people with similar medical issues, or other carers. Your cancer team may know of some.

See our section ‘other helpful websites’ below for contact details of relevant organisations. You may also find our general cancer articles helpful.

Frequently asked questions

  • If you have symptoms that might be linked to bowel cancer your GP may recommend that you have a rectal examination. This means they’ll feel inside your rectum (back passage) with their finger.

    Although it may feel a little strange and uncomfortable, it doesn’t hurt and only takes a minute or two.

    Your doctor will make sure that the examination is done privately. Your couch may be behind a curtain or they may lock the door so that no one can enter the room unexpectedly. You can ask for someone to be with you during the examination if you wish.

    You’ll be asked to remove your lower clothing and lie on your left side on the couch, with your knees drawn up.

    Your GP will put a glove on one hand and lubricate their finger with a gel. They’ll gently and slowly slide one finger into your back passage. You may feel their finger moving around. They will check for any lumps or abnormalities inside your rectum.

    Your GP will then remove their finger and let you know that they’ve finished. If you need some tissue to wipe away any excess gel, your GP will give you some. You can then get dressed again and your GP will discuss with you what they found.

    It’s important not to put off seeing your GP about your symptoms because you’re worried about having a rectal examination. There’s no need to feel embarrassed – it’s an important medical test that your GP has done many times before. And it’s a really quick and easy test to help your GP diagnose problems with your bowel.

  • Yes, there’s an increased chance of getting bowel cancer if you have inflammatory bowel diseases such as Crohn's disease and ulcerative colitis.

    These diseases cause your bowel to become inflamed. This inflammation can continue for a long time, sometimes for the rest of your life. Over time, the damage caused to the lining of your bowel increases the risk of cancer developing.

    Your risk of getting bowel cancer increases the longer you have Crohn’s disease or ulcerative colitis. It also depends on how much of your bowel is affected.

    If you’ve had Crohn's disease that affects the large bowel or ulcerative colitis for 10 years, your doctor will probably offer you regular bowel cancer screening. How often you’re tested will depend on your risk and may vary between once a year and once every five years. Ask your doctor about your risk of bowel cancer and whether you should be screened.

  • You might do, but it may only be temporary.

    If you have bowel cancer you’ll probably have surgery to remove part of your bowel. To rest the bowel, or if the two ends can’t be brought together, your surgeon may form a stoma (artificial opening). This means they’ll bring part of your bowel through the wall of your abdomen (tummy) to open onto the surface of your skin.

    When a stoma is formed from your large bowel, it’s called a colostomy. When it’s formed from your small bowel, it’s called an ileostomy.

    You’ll need to wear a bag over the stoma to collect your bowel movements. The stoma is usually placed low down on your abdomen (tummy) so you can hide it under your clothes.

    If you have a colostomy or ileostomy after surgery for bowel cancer, it’s often temporary. If so, you’ll have another operation called a stoma reversal a couple of months later to rejoin your bowel and remove the stoma. Sometimes, if your bowel can't be rejoined, your stoma will be permanent.

    Ask your surgeon if having a stoma might be part of your treatment. If it is, they’ll arrange for a specialist stoma nurse to talk to you about how to care for your stoma. Your nurse will be able to answer any questions or concerns you have. You may also find it helpful to look at our information on stoma care. For more information, help and support see the organisations listed below in ‘other helpful websites’.

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Related information

    • Colorectal cancer. BMJ Best practice., last reviewed April 2018
    • Colon cancer. Medscape., updated 24 April 2018
    • Large intestine anatomy. Medscape., updated 28 June 2016
    • Colorectal cancer. PatientPlus., last checked 20 January 2015
    • Rectal examination. PatientPlus., last checked 24 November 2014
    • Screening for the early detection of colorectal cancer. PatientPlus., last checked 5 June 2015
    • Ulcerative colitis. PatientPlus., last checked 24 June 2016
    • Crohn’s disease. PatientPlus., last checked 13 July 2013
    • Colorectal cancer. The MSD Manuals., last full review/revision October 2017
    • Gastrointestinal tract (lower) cancers - recognition and referral. NICE Clinical Knowledge Summaries., last revised September 2015
    • Colorectal cancer: diagnosis and management. National Institute for Health and Care Excellence (NICE), 2011 (updated 2014).
    • Suspected cancer: recognition and referral. National Institute for Health and Care Excellence (NICE), 2015 (updated 2017).
    • Quantitative faecal immunochemical tests to guide referral for colorectal cancer in primary care. National Institute for Health and Care Excellence (NICE), 2017.
    • Colorectal cancer. Oxford handbook of oncology (online). Oxford Medicine Online., published September 2015
    • Bowel cancer statistics. Cancer Research UK., accessed 8 May 2018
    • Bowel cancer. Cancer Research UK., last reviewed 30 September 2015
    • Bowel cancer screening: programme overview. Public Health England., last updated 9 August 2017
    • Bowel cancer screening. NHS Choices., last reviewed 12 February 2018
    • Having a stoma. The Association of Coloproctology of Great Britain and Ireland., accessed 10 May 2018

  • Reviewed by Dr Kristina Routh, Freelance Health Editor, Bupa Health Content Team, May 2018
    Expert reviewer, Mr Stephen Pollard, Consultant Surgeon
    Next review due May 2021