Bowel cancer also called colorectal cancer can involve the colon or rectum, the last parts of the digestive tract. Bowel cancer often develop from polyps, which are small abnormal growths in the walls of the colon. It is the second most common form of cancer and usually occurs in people over the age of 50.
You may have an increased likelihood of developing bowel cancer if you have a history of colon or rectal polyps, a previous history of bowel cancer, a family history of bowel cancer, chronic inflammatory bowel disease, Inherited syndromes e.g. familial adenomatous polyposis (FAP) and Lynch Syndrome (HNPCC).
Low fibre, high fat diet, A sedentary life style, Diabetes, Obesity, Smoking, Heavy alcohol intake and exposure to radiation therapy.
Bowel cancer may be associated with:
- Bloody stools
- A change in the bowel habits such as diarrhoea, constipation or narrow stools
- Unexplained weight loss
- Abdominal pain
Many people experience no symptoms in the early stages of the disease
For those above 50 who do not have symptoms of bowel cancer, a simple test called a faecal occult blood test (FOBT) is recommended once every 2 years. There is a strong push to prepone the screening age from 50 to 40 as we are diagnosing bowel cancers much earlier than previously detected. The test identifies hidden traces of blood within the stools and can help in the early detection of bowel cancer. A positive test would entail further investigation.
To diagnose bowel cancer your doctor will review your symptoms and medical history and perform a physical examination.
Certain diagnostic procedures may be carried out such as:
- Colonoscopy- A procedure done to look inside the entire colon. It is performed using an instrument called a colonoscope. A flexible tube with a tiny camera attached to one end which is connected to a large screen for viewing the internal structures.
- Sigmoidoscopy- A procedure using an instrument called a colonoscope to examine the last parts of the colon and the rectum. The name sigmoidoscopy is rather confusing.
- CT Colonography- A procedure in which a CT scan of the large intestine is performed after the colon is inflated with gas. A 3-dimensional view can be generated from the images.
If colon cancer or a polyp is detected, a colonoscopy is performed to confirm the diagnosis and then staging is performed to determine the size, location, and stage of the cancer. Staging is performed using computed tomography (CT) scan of the abdomen, MRI pelvis for rectal cancers, blood CEA a tumour marker, and routine blood tests.
Treatment would depend on the size, location, and stage of the cancer.
You can reduce your risk of bowel cancer and protect yourself from this condition by eating a well-balanced diet, eat variety of fruits, vegetables and whole grains, avoiding burnt or charred meat, limiting red meat, getting 30-60 minutes of exercise a day, maintaining a healthy weight, limiting alcohol, avoiding smoking and periodically screening for bowel cancer after the age of 50.