What is bowel cancer?

Bowel cancer, also known as colorectal cancer, can affect any part of the colon or rectum; it may also be referred to as colon cancer or rectal cancer, depending on where the cancer is located.

The colon and rectum are parts of the large intestine.

Colon

The colon is the longest part of the large intestine (the first 1.8 metres). It receives almost completely digested food from the caecum (a pouch within the abdominal cavity that is considered to be the beginning of the large intestine), absorbs water and nutrients, and passes waste (stool/faeces/poo) to the rectum.

The colon is divided into four parts:

1. the ascending colon is the start of the colon. It is on the right side of the abdomen. It continues upward to a bend in the colon called the hepatic flexure.
2. the transverse colon follows the ascending colon and hepatic flexure. It lies across the upper part of the abdomen. It ends with a bend in the colon called the splenic flexure.
3. the descending colon follows the transverse colon and splenic flexure. It is on the left side of the abdomen.
4. the sigmoid colon is the last part of the colon and connects to the rectum.

The proximal colon is the ascending colon and the transverse colon together.

The distal colon is the descending colon and the sigmoid colon together.

Rectum

The rectum is lower part of the large intestine (the last 15 centimetres) that connects to the sigmoid colon. It receives waste (stool/faeces/poo) from the colon and stores it until it passes out of the body through the anus.

Anus

The anus is the opening at the lower end of the rectum through which waste is passed from the body.

Cancer in the anal canal or anus is treated differently from, and is less common than, bowel cancer.

Symptoms of bowel cancer

Not everyone experiences symptoms, particularly in the early stages of bowel cancer.

The common symptoms may be suggestive of bowel cancer, but they can also be due to other medical conditions, some foods or medicines.

Don’t delay in talking to your GP if you are experiencing any of the described symptoms for two weeks or more, because when diagnosed early almost 99 percent of bowel cancer cases can be successfully treated.

Blood in your poo or rectal bleeding is not normal and should never be ignored.

Common symptoms can include:

• Blood in your poo or rectal bleedingBright red or very dark blood should never be ignored
• A recent, persistent change in bowel habit
  Such as looser, more diarrhoea-like poo, constipation, or going to the toilet more often, or trying to go – irregularity in someone whose bowel habits have previously been regular
• A change in shape or appearance of your pooFor example, narrower poos than usual or mucus in poo
• Frequent gas pain, crampsA feeling of fullness or bloating in the bowel or rectum
• Unexplained anaemiaA low red blood count causing tiredness, weakness or weight loss
• A feeling that the bowel has not emptied completely after going to the toilet
• Pain or a lump in the anus or rectum
• Abdominal pain or swelling