What you need to know about bowel cancer

Bowel cancer (also called colorectal cancer) is a common illness caused by uncontrolled cell growth in the large intestine or rectum. It can often start with small, non-cancerous growths called polyps that may eventually turn into cancer over several years if not removed.

What is bowel cancer?

Bowel cancer starts when the cells that line the colon or rectum grow out of control. Often, it begins with small growths called polyps. Although not all polyps turn into cancer, some can become malignant if they are not removed over time.

In the UK, bowel cancer is a major health issue - there are over 44,063 new cases each year, making it the fourth most common cancer [1]. It occurs more often in people over 60 and is slightly more common in men than women.

Why screening matters

Early detection of bowel cancer significantly increases the chances of successful treatment. Screening can help identify the presence of precancerous polyps or early-stage cancers when treatment is most effective. By participating in regular screening programmes, individuals can take a proactive step in safeguarding their health.

The benefits of early detection

Finding bowel cancer early can make treatment simpler and more effective. Regular screening can help:

• Catch cancer early: Which means treatment is often more successful.

• Remove polyps: In many cases, polyps can be detected and removed before they turn into cancer.

• Lower your risk: Regular screening has been shown to reduce deaths from bowel cancer by up to 25-30% [2].

Screening for bowel cancer

Provided by our Virtual GP partner, Teladoc Health

What are the screening tests?

Several screening tests are available to help detect bowel cancer early:

• Stool Testing (FIT):
  The Faecal Immunochemical Test (FIT) checks for hidden blood in the stool. This simple test is mailed to those aged 60-74 every two years. If the test is positive, further investigations will be arranged.

• Sigmoidoscopy:
  A sigmoidoscopy uses a flexible tube with a camera to look directly into the lower part of the bowel (the sigmoid colon and rectum), where most cancers are found. In some UK regions, this test is the primary screening tool, though many now begin with FIT.

• Colonoscopy:
  For a more detailed look, a colonoscopy examines the entire colon with a longer scope. This test is often used if FIT returns a positive result or if someone is at higher risk due to a family history of colorectal cancer.

• CT Colonography (Virtual Colonoscopy):
  This scan uses multiple x-rays to create detailed images of the colon. It is a good option for older or frailer patients who may not be able to handle a colonoscopy. If abnormalities are found, a colonoscopy may still be necessary.

Are the tests effective?

Yes. Bowel cancer screening tests are very effective in detecting cancer early:

• Early treatment: Early detection makes treatment simpler and increases the chance of curing the cancer.

• Preventative benefits: Some tests can detect and allow the removal of polyps before they develop into cancer.

• Lower mortality: Regular screening can reduce deaths from bowel cancer by as much as 25-30%.

Although no screening method is 100% perfect, the benefits of knowing your health status far outweigh the minimal risks.

Recognising the signs and symptoms

Knowing what changes might signal a problem is important. Look out for:

• Changes in bowel movements: Diarrhea, constipation, or a change in how your stool looks.

• Blood in the stool: This might be visible or hidden.

• Abdominal pain: Persistent discomfort or pain.

• Unexplained weight loss: Losing weight without trying may be a warning sign.

Even if you experience one or more of these signs, keep in mind that early bowel cancer often does not cause any symptoms at all. This is why screening is so valuable.

Taking action

• Talk to your doctor: If you are over 50, have a family history of bowel cancer, or notice symptoms, ask about screening options.

• Participate in the NHS screening programme: In the UK, most people aged 60–74 are invited for regular screening to catch any early signs of bowel cancer.

• Stay informed: Understanding your options helps you take control of your health.

Unless you have specific reasons not to, it’s a good idea to participate in the NHS screening programme. If you notice symptoms or have a family history of bowel cancer, talk to your clinician about whether you might need more specific investigations or an enhanced screening programme. 

Bowel cancer is a serious but manageable condition if caught early. By understanding what bowel cancer is, watching for signs, and making screening a regular part of your healthcare routine, you can help protect yourself and potentially save your life. Remember, staying proactive about your health is the first step towards prevention.

1. Bowel cancer statistics, Cancer Research UK, https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/bowel-cancer

1. Bowel cancer screening standards data report 2023-25, Gov.uk, https://www.gov.uk/government/publications/bowel-cancer-screening-annual-report-2023-to-2024/bowel-cancer-screening-standards-data-report-2023-24