What is bowel cancer?

Bowel cancer is the fourth most common type of cancer in the UK, with around 42,900 new diagnoses of bowel cancer in the UK each year, according to Cancer Research UK. Early diagnosis and rapid access to the best possible treatment means that long term survival is becoming more and more common, even for some cases of secondary bowel cancer.

The bowel, also called the intestine, is part of your digestive system. It’s split into two sections, which are the small and large bowel. When we talk about bowel cancer, we’re usually referring to the large bowel, but cancer can occasionally form in the small bowel. Depending on the location of the cancer, it can be called large bowel or colon cancer, colorectal cancer, or rectal cancer. 

There are several options for treating bowel cancer, and the outcomes are improving owing to better treatment options and early diagnosis. Bowel cancer treatment may include surgery (resection or a colectomy), chemotherapy, radiotherapy, targeted therapies, immunotherapy and a specialist diet. Very often a treatment plan can include a combination of treatments, with chemotherapy and radiotherapy often being used together before or after surgery.

At GenesisCare, we combine these with consultant-led integrative cancer care, such as personalised exercise medicine, wellbeing therapies and psychological support, to help you achieve the best possible outcome. Our qualified physiotherapists and wellbeing consultants will carefully plan these therapies tailored to your needs by working with you and your consultant. 

Types of bowel cancer

Your bowels are split into two main sections, the small bowel and the large bowel. This page is about large bowel cancers. You can find out more about small bowel cancers here.  

Large and small bowel cancer are also types of gastrointestinal cancer, as your bowels form part of the gastrointestinal (GI) system, also known as your digestive system. 

The type of bowel cancer depends on where the cancer started. 

Colon cancer

Cancer that starts in the large bowel (the colon) is called colon cancer. It can start from tiny bumps called colon polyps that grow inside the lining of your colon. They’re normally harmless but sometimes they can develop into cancerous tumours. If undetected, tumours can spread to other parts of your body.

Rectal cancer

Cancer that starts in your rectum is called rectal cancer. Rectal cancer also begins as polyps that grow in your rectal lining. These can sometimes develop into cancerous tumours.

Although it starts similarly to colon cancer, the treatment for rectal cancer is different. Treatment can also depend on the stage of your cancer. 

Book an appointment

Contact us today to find out more about our bowel cancer services and how we can help you

Bowel cancer signs and symptoms

Having symptoms of bowel cancer doesn’t always mean bowel cancer. Often, the signs and symptoms are caused by other conditions. It’s important to get checked out as soon as possible, because finding cancer early can improve outcomes.

  • Changes in bowel habit
  • Diarrhoea or constipation
  • Feeling like you need to go again after a bowel movement
  • Pain when passing bowel movements
  • Blood in the stool or on the tissue, which can be red or black
  • Mucus in the stool
  • Nausea and vomiting
  • Abdominal (stomach) pain or cramping
  • Unexplained weight loss or loss of appetite
  • Tiredness
  • Low red blood cell count (anaemia)

You can read more about the signs and symptoms of bowel cancer and what happens next here.

Sometimes, bowel cancer can cause a complete or partial blockage of the large bowel. This can cause: 

  • Abdominal (stomach) pain
  • Vomiting
  • Constipation
  • Bloating

If you think you have blocked bowels, go to your nearest accident and emergency department (A&E) immediately. 

If you experience any signs and symptoms of bowel cancer, it’s important to speak to your GP. You can also book directly with us and be seen by a leading cancer expert. 

Causes of bowel cancer

Bowel cancer starts with a mutation that causes bowel cells to grow too quickly, forming tumours. These often start in polyps, which are small growths in the intestines that look like skin tags.

Up to 1 in 10 cases of bowel cancer is genetic, caused by a faulty gene that can be passed down within a family. Genetic conditions linked to bowel cancer include Lynch syndrome, FAP (Familial Adenomatous Polyposis) and MAP (MUTYH Associated Polyposis).

It’s not always known what causes colon and rectal cancer, but there are several risk factors. These increase your chance of developing bowel cancer. 

Bowel cancer risk factors

  • Being over 50
  • Having a close relative with bowel cancer
  • Not eating enough fibre
  • Smoking
  • Being obese
  • Drinking a lot of alcohol
  • Regularly eating red or processed meat
  • Some bowel conditions, such as Crohn's disease pr ulcerative colitis
  • Type 2 diabetes

Bowel cancer diagnosis

At GenesisCare, we diagnose and treat a wide range of cancers, and we understand that this can be a worrying time. Our diagnostic services are first-class, and our commitment is to give you the answers you need, as quickly as possible.

It‘s important to remember that symptoms can often be caused by other conditions and aren’t always bowel cancer. But, whatever your diagnosis, we can make sure you get the expert care you need – without delay. 

How is bowel cancer diagnosed?

If you‘re concerned about bowel cancer symptoms, we offer specialist

bowel cancer tests and diagnostics in our centres. Here you‘ll see one of our expert consultants who specialise in cancers affecting the colon and rectum. 

They‘ll assess your symptoms and, if necessary, refer you for diagnostic tests such as a digital rectal examination (DRE), faecal immunochemical test (FIT), flexible sigmoidoscopy, proctoscopy, colonoscopy, blood tests, biopsy or imaging scans (including CT, PET-CT, MRI or ultrasound). You may also need to see one of our specialist dietitians.

Bowel cancer screening

Bowel screening checks for signs of bowel cancer when there are no symptoms. This can help find cancer earlier. If you’re between 60 to 74 years old, the NHS offers bowel screening checks every two years. However, if you have symptoms you should speak to your GP or contact us, no matter your age.

Bowel cancer treatment overview

There are several options of treatment available for large bowel cancer, such as:

  • Surgery - removal of part or all of the large bowel
  • Chemotherapy - anti-cancer drugs which destroy the cancerous cells
  • Radiotherapy - high-energy radiation beams which are targeted at the cancer cells
  • MRIdian radiotherapy - advanced radiotherapy that can be used to eradicate secondary tumours
  • Targeted therapy - a specialised groups of drugs that attack or block certain processes in the cancer cells
  • Immunotherapy - drugs that help your body's immune system recognise and fight the cancer


Treatment side effects

No treatment is without side effects. These will depend on the extent and duration of your treatment. Your doctor will explain these to you before you start your treatment, together with the ways your treatment plan and supportive care can help manage or minimise these.

For some people, bowel cancer treatment has mild and temporary side effects. But for others, life will look a little different due to long-term or permanent changes to bowel habits, the bladder, or their sex life. 

However, treatments and techniques are helping minimise the impact treatment has on you.

How is bowel cancer treated?

Why choose us?

From prompt investigation of worrying symptoms through to comprehensive treatment of advanced bowel cancer, we offer world-class treatment and care tailored to every patient.

We equip our centres with the latest technologies and offer many of the newest bowel cancer tests, scans and treatments that are proven to be safe and effective. Our consultants are regional and national cancer experts who focus on you to achieve the best outcomes possible and minimise side effects.

With us, you’ll receive the very best personalised care and a treatment plan that embraces lifestyle-enhancing approaches through our integrative cancer care programme, including exercise medicine and wellbeing therapies.    

Book an appointment

Contact us today to find out more about our bowel cancer services and how we can help you


Reviewed by:

Dr James Good
Clinical Oncologist
May 2024

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