The first step in diagnosis is usually an examination of your rectum by a doctor. You may also be asked to take a stool sample to your doctor so it can be tested for blood. If your doctor thinks that cancer may be present, or is unable to provide a diagnosis, they will refer you to a specialist. The following tests are all used in the diagnosis of colorectal cancer.

• Digital rectal examination

  This is usually the first check for colorectal cancer. It involves a doctor gently inserting a gloved finger into the rectum to check for any lumps or swellings.

• Fecal immunochemical test (FIT)

  This is a type of faecal occult blood test to detect the presence of human blood in a single stool sample. Those with abnormal results are then invited for further testing.

• Colonoscopy

  In this procedure, a doctor or nurse will gently pass a flexible tube (a colonoscope) into your back passage. The tube is flexible and can be used to examine the entire length of the large bowel.

• Barium enema

  This is a special X-ray of the large bowel. The barium (a white liquid) ensures that a clear image can be taken.

Further tests

If tests indicate that you have colorectal cancer, your doctor may wish to conduct further tests to see if the disease has spread. The results will help your doctor decide the best type of treatment.

• X-ray

  This is used to test if colorectal cancer has spread to the lungs.

• Computerised Tomography (CT/CAT) scan

  A CT scan is a type of X-ray in which pictures are taken of a specific area and fed into a computer to form a detailed picture of inside the body.

• Ultrasound scan

  In this test, sound waves are used to form a picture of the liver and inside the abdomen.

• Liver function test

  This blood test measures chemicals that are normally found or produced in your liver. An abnormal result can indicate that cancer has spread to the liver.

• Magnetic Resonance Imaging (MRI) scan

  MRI is a diagnostic test that uses a combination of magnetism and radio waves to create detailed cross-sectional images of your body.