Bowel Cancer FAQs

Overview

Bowel cancer, also known as colorectal cancer, is the third most common malignancy globally, with lung and breast cancers being the first and second, respectively. According to the World Health Organization (WHO), the incidence of colorectal cancer (i.e. the number of new cases per year) will increase by 63% worldwide by 2040. Thus the burden of bowel cancer is projected to rise significantly over the coming years.

The United Kingdom, amongst several other countries, has national screening and educational programmes for colorectal cancer which have helped to lower the incidence of bowel cancer and enabled early detection of the disease.¹ 

If you have questions about bowel cancer and would like to find out more about the disease, this article aims to help. We will cover some of the most frequently asked and important questions about bowel cancer.

What is bowel cancer?

Bowel cancer, as the name suggests, affects the large bowel and occurs when abnormal cells in the inner lining of the bowel grow and divide in an uncontrolled manner. Abnormal growth of clusters of cells in the bowels, called polyps, commonly develop initially and are known as pre-cancerous. This means that they have the potential to become cancerous over time. Once these polyps change and become malignant, they develop into cancer. This may involve cancer invading the lining of your bowels and other organs.

Does bowel cancer affect a specific area?

The term colorectal cancer summarises this well. The ‘colo-’ part indicates that the colon (the large intestines) are affected and the ‘rectal’ part indicates the involvement of the rectum, i.e. the lower end of the bowels responsible for storing faeces before defecation. In addition to this, the small intestines (higher up the digestive tract) and other nearby structures may be affected. 

Bowel cancer does not have to involve all of those areas at once. It may start in one region and involve other parts of the bowel at a later stage or remain in one section only. Also, the whole colon does not have to be affected – for example, individuals may have cancer of the sigmoid colon only, as opposed to the entire loop of large intestines. 

Will I have colorectal cancer if I have polyps?

There is no definite answer until further investigations and assessments are done. Colon polyps are common, especially with advancing age and most are benign (i.e. non-cancerous) and usually do not cause symptoms. However, some polyps might change over time and develop into bowel cancer, which is why screening and seeking medical attention is important. 

What causes bowel cancer?

The causes of bowel cancer are likely multifactorial, meaning that it could be due to a combination of genetic factors, lifestyle, and other medical conditions.² Genetic factors could be random changes in your genes (mutations), or inherited abnormalities. If a first-degree family member has had a diagnosis of colorectal cancer, there is a higher risk of having the malignancy. For example, if person A’s father had bowel cancer, then person A has a risk factor for developing it as well. By comparison, the risk is not as high if their cousin has it. 

Lifestyle is a major topic in bowel cancer. Evidence supports the role of exercise in reducing the risk of developing colorectal cancer.³ Individuals with poor diets, including low fibre intake, lots of processed foods, high red meat intake, and high alcohol use, have an increased likelihood of developing bowel cancer. Smoking is also a key risk factor for colorectal cancer, as it is for numerous other forms of cancer. 

Can colorectal cancer affect young people?

The short answer is yes. However, those most often affected by bowel cancers are older adults, typically people over the age of 50. In the UK, incidence rates are most high among those aged 85-89. In many cases of bowel cancer in young people, it is not uncommon for there to be a personal or family history of other cancers and/or medical conditions such as inflammatory bowel disease and Lynch syndrome.

What are the signs and symptoms of colorectal cancer?

There are numerous ways in which bowel cancers can present. Bowel Cancer UK has great resources on the signs and symptoms that one might expect and some explanations for each major symptom. Generally speaking, if you experience changes to your bowel movements, have blood in your stools, or experience tummy pain that has no clearly identificable explanation, you should see a doctor. 

How is bowel cancer screened for?

Screening programmes for bowel cancer differ across countries. In England, the Faecal Immunochemical Test (FIT) is offered to anyone between 54 and 74 years of age. This is a test kit for home use that is automatically sent by the NHS every two years to people living in England who are registered with a GP. This test will identify small traces of blood in the stool, which could signal the presence of colorectal cancer. It is important to remember that you do not need to have any symptoms or concerns to be eligible to take the FIT test and that a positive result does not necessarily mean you have bowel cancer. 

Do I use the FIT kit if I have signs and symptoms?

In The UK, the FIT used for screening healthy adults in the National Bowel Cancer Programme is the same test that is used to guide the management of patients who visit a GP with signs and symptoms associated with bowel cancer. The test helps GPs to detrmine which patients should be referred to a specialist for further tests, such as colonoscopy and imaging.⁴ When used in symptomatic patients, the threshold for determining a positive result is lower than that used in the national bowel screening programmes. 

What is a colonoscopy?

A colonoscopy is a type of endoscopy. It is a procedure where a thin and flexible tube with a camera and light at the end is inserted into the backside to look for any changes or abnormalities in the rectum and bowels. A type of colonoscopy commonly done in such cases is flexible sigmoidoscopy that examines the lower third of the large intestine). The procedure itself can involve taking a biopsy (a sample of a small piece of tissue to be examined under a microscope), which will allow your clinicians to find out more about what changes are happening to the bowels. Thus, a referral for colonoscopy is important for investigations (and can be used to identify other conditions) but it does not mean that a person has bowel cancer. 

Is bowel cancer curable?

If detected early, it can be curable. When it is only localised to the bowel, it is highly treatable and the prognosis can be good to excellent in some cases. The prognosis and survival for bowel cancers depend on the level of invasion, the type of tumour itself (i.e., if it’s more or less aggressive) and whether it has spread to other sites. Around 90% of people diagnosed with stage 1 bowel cancer will survive the condition for five or more years after diagnosis. The five-year survival rates for stage 2 bowel cancer is 85% and for stage 3 it is 65%.

The treatment options for bowel cancer include: 

• Surgery. The specific type of surgery will depend on the cancer’s type, size and location
• Chemotherapy 
• Radiotherapy 
• Palliative management will be offered to patients with advanced cases 

Will I have a stoma?

A stoma is an abdominal opening that is linked to either your bowels or urinary tract to allow waste to leave the body. People receiving surgical resections for bowel cancer may have a stoma, but this is not always the case. Stomas are made based on expert decisions and are important for people who have had large sections of their bowels removed, or where a functional connection between the intestines, the rectum and/or the anus cannot be made. So while it is possible to have surgical treatment for bowel cancer without the need for a stoma, whether or not you will need a stoma depends on the type and stage of the cancer and how much of the bowel needs to be removed. 

Can someone live without a colon?

With the appropriate management, yes. This is where stomas are useful. However, you will notice that the consistency and frequency of your ‘output’ is different. That’s because the colon usually helps with the bulking of the stools, reabsorbing nutrients and water and later this stool would be stored until a person is ready for defecation. 

Where can I get more support?

You can call the NHS bowel cancer screening helpline for information on the screening program. The NHS, Cancer Research UK, and Bowel Cancer UK are great resources for learning more about colorectal cancer and supporting you or others throughout the journey. Services offered by Bowel Cancer UK include: ‘Ask The Nurse’, online communities, peer support line and support groups. Macmillan Cancer Support provides help for anyone affected by cancer and has a free helpline that is open every day between 8am and 8pm (0808 808 00 00).

Summary

Bowel cancer, also known as colorectal cancer, affects the large bowel and can start as non-cancerous polyps, which may become cancerous over time. It typically occurs in older adults but can also affect younger people, especially if there's a family history of cancer. Key risk factors include genetics, lifestyle choices such as poor diet, smoking, and lack of exercise.

Common symptoms include changes in bowel habits, blood in stools, and unexplained abdominal pain. Screening programs like the FIT test help detect early signs of the disease, even in people without symptoms. If bowel cancer is caught early, it is often curable. Treatment options include surgery, chemotherapy, and radiotherapy. In some cases, a stoma may be needed after surgery.

Resources for more information and support include Bowel Cancer UK, NHS services, and Macmillan Cancer Support.