Diagnosis

How is bowel cancer diagnosed?

A number of tests can be performed to diagnose bowel cancer. You may have some or all of the following tests:

Rectal examination

The doctor inserts a gloved finger into your rectum to check for any lumps, swelling or bleeding.

Abdominal examination

The doctor will gently feel the surface of your abdomen to check for any lumps.

Blood count

A sample of your blood is taken to count the number of red cells in your blood (a low level (anaemia) can be a sign of bowel cancer).

Carcinoembryonic antigen (CEA)

CEA is a blood test that looks at a protein in the blood. It is sometimes raised in people with bowel cancer. However, it is not a reliable test to diagnose bowel cancer.

A test for blood in the bowel motions

(faecal occult blood)

Barium enema

The barium shows up on the X-rays and gives a clear picture of your bowel.

CT colonography (also known as virtual colonoscopy)

This X-ray technique is increasingly replacing barium enemas. The colon is emptied with a laxative. Air is then gently pumped into your bowel via your anus. CT scans are taken of your abdomen. If abnormalities are found then this would usually lead onto a colonoscopy.

Sigmoidoscopy

The doctor examines your rectum and the lower part of your bowel using a short tube (usually straight but may be flexible) called a sigmoidoscope. The doctor may also take a biopsy (a small sample of tissue).

Colonoscopy

The doctor or nurse inspects the entire length of your large bowel by gently inserting a long, flexible tube with a video camera in it called a colonoscope. This is passed through your anus and rectum into your colon. A sedative may be given before the colonoscopy.

Removing polyps at colonoscopy

If you have a pre-cancerous lesion, such as an adenomatous polyp of the colon or rectum, your surgeon or gastroenterologist may just remove the polyp from the bowel lining. A border of healthy tissue will also be removed. This is called a local resection.

Removal of a polyp

If there are any cancer cells within the polyp, your surgeon may decide you need a second, larger operation. This is to remove any cells that may have been left behind, and to make sure that the cancer is unlikely to come back.