Colon cancer

Bowel cancer screening is a way of finding bowel cancer at an early stage before it causes symptoms.

This is when part of the bowel becomes blocked. It may cause symptoms such as tummy pain, nausea and vomiting, and constipation.

A rectal examination is when the doctor places a gloved finger into your back passage to feel for any lumps or swelling.

You will usually have a blood test to check your level of red blood cells. If you have a low number of red blood cells, this is called anaemia. You will also have blood tests to check whether your liver and kidneys are working normally.

A colonoscopy looks at the inside of the whole length of the large bowel. You can usually have this test as an outpatient. It takes about an hour.

In a virtual colonoscopy a computerised tomography (CT) scanner takes a series of x-rays. This builds up a three-dimensional picture of your bowel.

A sigmoidoscopy looks at the inside of the rectum and the part of the colon closest to the rectum (the sigmoid colon). You can usually have it as an outpatient.

Your blood may be tested for a protein called carcinoembryonic antigen (CEA). Some people with bowel cancer have higher levels of this protein.

A CT (computerised tomography) scan uses x-rays to build a three-dimensional (3D) picture of the inside of the body.

An MRI scan uses magnetism to build up a detailed picture of areas of your body.

A PET-CT scan is a combination of a CT scan, which takes a series of x-rays to build up a three-dimensional picture, and a positron emission tomography (PET) scan. A PET scan uses low-dose radiation to measure the activity of cells in different parts of the body.

Surgery is often used to remove cancer or areas affected by the cancer. It may also be used to help control symptoms.

Chemotherapy uses anti-cancer drugs to destroy cancer cells. You may have it as your main treatment or with other cancer treatments such as surgery.

Targeted therapy drugs target something in or around a cancer cell that is helping it grow and survive. Targeted therapies are sometimes used to treat bowel cancers (colon or rectal) that have spread to other parts of the body.

Below is a sample of the sources used in our colon cancer information. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

National Institute for Health and Excellence (NICE). Colorectal cancer: diagnosis and management clinical guidelines. Updated December 2014. Available from www.nice.org.uk/guidance/cg131 (accessed October 2019).

Association of Coloproctology of Great Britain & Ireland (ACPGBI). Volume 19. Issue S1. Guidelines for the management of cancer of the colon, rectum and anus. 2017. Available from www.onlinelibrary.wiley.com/toc/14631318/19/S1 (accessed October 2019).

BMJ. Best practice colorectal cancer. Updated 2018. Available from www.bestpractice.bmj.com/topics/en-gb/258 (accessed October 2019).

European Society for Medical Oncology (ESMO). Early colon cancer: ESMO clinical practice guidelines. Published in 2013. Updated 2019. Available from www.esmo.org/Guidelines/Gastrointestinal-Cancers/Early-Colon-Cancer (accessed October 2019).

MA Rodriguez-Bigas, A Grothey et al. Overview of the management of primary colon cancer. Uptodate 2019. Available from www.uptodate.com/contents/overview-of-the-management-of-primary-colon-cancer (accessed October 2019).

This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Chief Medical Editor, Professor Tim Iveson, Consultant Medical Oncologist.

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