Colorectal Cancer

What is colorectal cancer? 

Colon cancer is cancer of the large intestine (colon), the lower part of your digestive system. Rectal cancer is cancer of the last several inches of the colon. Together, they are often referred to as colorectal cancer. They may also be referred to as bowel cancer. 


There are a number of factors which might increase your risk of developing colorectal cancer: 

  • Age: more common in people over 50 years of age. 
  • Alcohol: more common in people with a high consumption level. 
  • High calorie diet.
  • Low-fibre diet. 
  • Smoking. 
  • Ulcerative colitis: patients with a history of this condition. 
  • Crohn’s disease: patients with a history of Crohn’s disease or irritable bowel syndrome. 
  • Polyps: presence of polyps in the colon or rectum may eventually become cancerous. 

What are the symptoms? 

The symptoms of colorectal 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 stomach. 
  • Weight loss. 
  • Tired and breathless (due to anaemia from blood loss). 
  • Rectal bleeding or blood in stools. 

How is colorectal cancer diagnosed? 

If you are concerned about colorectal cancer, there are a number of tests that your GP can carry out for you before referring you to hospital for further investigation: 


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. 


Faecal occult blood test 

This is also referred to a stool sample. The test checks your bowel motions for tiny amounts of ‘hidden blood’. Blood in your bowel motions can be caused by bowel cancers and polyps. It is used to identify people who may be at risk of developing bowel cancer. 


Blood tests 

General blood tests used to check for anaemia in a patient. 


If after these tests your GP feels that further testing is required, they may refer you to hospital for some of the following tests: 


Left sided colonoscopy

A left sided colonoscopy is a visual examination of the inside of the rectum (back passage) and sigmoid colon (bowel). It is performed by passing a small flexible tube through the rectum into the lower left side of the colon. During the examination biopsies may be taken as necessary. 


Full colonoscopy 

A full colonoscopy is a visual examination of the lining of the bowel. It is performed by passing a small flexible tube through the rectum into the colon. During the examination biopsies may be taken. 


Barium enema 

This is a special x-ray of the large bowel. During the procedure, a mixture of barium (which shows up on an x-ray) and air is passed into the back passage using a small flexible tube. It's important to keep the mixture in the bowel until all the x-rays have been taken. The doctor can then watch the passage of the barium through the bowel on an x-ray screen and look for any abnormal areas. 


Here in Mater Private Network in Dublin we offer a consultant-led Rapid Access Endoscopy service. If your GP refers you to us for diagnostic tests, you will be seen within a maximum of 10 days. 


Other tests may include: 

These scans will help the doctor to put a grading on the stage that the colorectal cancer is at and help them decide on the best treatment for your cancer. 

What is the treatment for this condition? 

Some of the possible treatments suitable for colorectal cancer include: 

  • Chemotherapy: medical treatment to destroy cancer cells. It may be used prior to surgery in an attempt to shrink the tumour 
  • Radiotherapy: uses high energy radiation beams to destroy cancer cells. It may be used before surgery in an attempt to shrink the tumour 
  • Surgery: the most common treatment for colorectal cancer. The affected part of the bowel is removed and any lymph nodes that are nearby. 

Some people may require radiotherapy and chemotherapy following surgery as both can help to prevent recurrence of the cancer.