Symptoms and diagnosis of bowel cancer


The symptoms of bowel cancer can include:

  • A change in your normal bowel motion, such as diarrhoea or constipation.
  • Feeling you have not emptied your bowel fully after a motion.
  • Pain or discomfort in your abdomen (tummy) or back passage.
  • Trapped wind or fullness in your tummy.
  • Weight loss.
  • Tired and breathless (due to anaemia from blood loss).
  • Rectal bleeding or blood in stools.
  • A lump in your tummy area.

These symptoms can also be due to complaints other than bowel cancer. But do get them checked out by your doctor, especially if they go on for more than 4 to 6 weeks.

For more information see our cancer prevention leaflet "Bowel cancer – What you should know (pdf 2.34MB)".


Testing for bowel cancer when you have no symptoms is called screening. There are plans to roll out a national bowel cancer screening programme in 2012. For more information on screening for bowel cancer visit the National Cancer Screening Service website. Screening involves a test that checks for hidden blood in your stools and a colonoscopy, if needed. Talk to your GP if you feel you or your family are at high risk.

If you are concerned about any of the above, please contact our helpline.


If you are worried about any symptoms of bowel cancer, visit your G.P. He or She can do a small number of tests first, such as;

  • Rectal exam
  • Blood tests to check for anaemia
  • Stool sample to check for hidden blood

Rectal exam

  • In this test your doctor puts a gloved finger into your back passage to feel for lumps or swelling. This quick test may be slightly uncomfortable but does not hurt.

Special tests

  • Proctoscopy
  • Sigmoidoscopy
  • Colonoscopy
  • CT colonography

Proctoscopy: In this test your doctor looks inside your back passage. To do this, he or she passes a short thin tube into your back passage while you are lying on your side. Air is then pumped in so that the doctor can see the area more clearly.

Sigmoidoscopy: A longer tube with a camera is used in this test. The tube is carefully put into your back passage. A light inside the tube helps the doctor see clearly. Your doctor can see any abnormal areas in one part of your bowel. He or she can take samples of the cells in your bowel. This is called a biopsy.

Colonoscopy: This test is like a sigmoidoscopy, except your whole bowel can be looked at. Photos and samples of your bowel can be taken during this test. This test can take about an hour and can be uncomfortable. You may be given sedation , just before the test ,to help you relax.

CT colonography: This is a newer test and not available in all hospitals. It is also known as a virtual colonoscopy. Air is put into your bowel by a tube put into your back passage. A number of CT scans are taken to look at your bowel. A biopsy cannot be taken during this test.

Other tests

  • CT scan
  • MRI scan
  • Ultrasound scan
  • PET scan

These scans can help to stage the cancer.

Learn more about the above tests

Staging of bowel cancer

The stage of cancer describes the size of your cancer and whether it has spread from its original area to other areas in the body. Knowing the stage of your cancer will help your doctor to decide on the best treatment for your cancer.

Your doctor will stage your bowel cancer using the TNM staging system. TNM refers to the size of the tumour (T), if it has spread to your lymph nodes (N), and if it has spread to other parts of your body as metastases (M). It is a complex system but it can be roughly described as the following:

Stage 1: The cancer is in the inner wall of your colon or rectum only.

Stage 2: The cancer is in the muscle layer of your colon or rectum and may have spread to nearby tissues.

Stage 3: The cancer has spread to nearby lymph nodes.

Stage 4: The cancer has spread to other parts of your body, for example your liver or lungs. This can also be called advanced cancer.

Call our National Cancer Helpline

Freephone 1800 200 700 to talk to a specialist cancer nurse
It's open Monday-Thursday from 9am to 7pm and Friday from 9am to 5pm