Bowel cancer is also known as colon, rectal or colorectal cancer.
The bowel runs from the stomach to the anus and is made up of two main parts - the small and large bowel.
The small bowel is the upper 600cms of bowel which absorbs your food and nourishment and only rarely is involved with cancer.
The large bowel is made up of the colon and rectum which is where most cancers affecting the bowel occur.
The lining of the bowel is made of cells that are constantly being renewed. Sometimes these cells grow too quickly, forming a clump of cells known as a bowel polyp (sometimes known as an adenoma). Polyps are not bowel cancers (they are usually benign), but they can change into a malignant cancer over a number of years. A malignant cancer is when cancer cells have the ability to spread beyond the original site and into other parts of the body. Once the cancer has spread to other parts of the body it is much more difficult to cure.
The cancer in the bowel may form an ulcer or remain small and cause a narrowing in the bowel. Cancers often bleed and this may be seen on or in the motion or - if it isn't noticed over a long period of time - can make the patient anaemic.
Around 40,000 people will be diagnosed with bowel cancer over the next year, slightly more men than women and at a younger age. More than half the people affected will be cured.