Symptoms of colon and rectal cancer

The symptoms of bowel cancer may include any of the following:

• blood in, or on the stools (bowel motions) – the blood may be bright red or dark in colour
• a change in your normal bowel habit (such as diarrhoea or constipation) for no obvious reason, lasting longer than six weeks
• pain in the tummy (abdomen) or back passage
• a feeling of not having emptied your bowel properly after a bowel motion
• unexplained weight loss
• unexplained tiredness.

The tiredness can happen if the cancer has been bleeding so the number of red blood cells is reduced (anaemia). Anaemia may also make you feel breathless. 

Sometimes the cancer can cause a blockage (obstruction) in the bowel. The symptoms of this are:

• being sick (vomiting)
• constipation
• pain in the abdomen
• a bloated feeling.

When to consult your doctor

Although these symptoms can be caused by conditions other than colon or rectal cancer, it’s important that you always have them checked by your doctor. As bowel cancer usually occurs in people over the age of 50, these symptoms in younger people are often thought to be due to other bowel problems, such as haemorrhoids (piles), irritable bowel syndrome (IBS) or ulcerative colitis.

If you have symptoms that don’t improve within a few weeks, or if your symptoms are getting worse, it’s important that you’re referred to a specialist for tests to find out what the problem is.