Colorectal cancer
Colerectal cancer is an umbrella term which refers to both colon cancer, which is the cancer of the large intestine (colon), together with rectal cancer which is cancer of the last several inches of the colon.
Most cases of colon cancer begin as small, noncancerous (benign) clumps of cells on the inside lining of the colon called adenomatous polyps. Over time some of these polyps become colon cancers.
Symptoms
Signs and symptoms of colon cancer include:
- A change in your bowel habits, including diarrhea or constipation or a change in the consistency of your stool for more than a couple of weeks
- Rectal bleeding or blood in your stool
- Persistent abdominal discomfort, such as cramps, gas or pain
- A feeling that your bowel doesn't empty completely
- Weakness or fatigue
- Unexplained weight loss
What causes colorectal cancer?
The exact causes of colorectal cancer are not known, however, like the majority of cancers it is believed that colorectal cancer develops as a result of a combination of environmental and genetic factors. Inherited gene mutations are believed to increase the risk of colon cancer, and a familial history of colon cancer will inrease the risk of developing this disease.
In addition, other factors are thought to contribute to the risk of developing colon cancer. These include older age, a personal history of colorectal cancer or polyps, inherited syndromes such as familial adenomatous polyposis and Lynch syndrome, a diet low in fibre and high in fat, a sedentary lifestyle, diabetes, excessive alcohol consumption and smoking.