The colon is that part of the digestive system where our body stores the undigested parts of the food we eat. At the end of the colon is the rectum which is adjoining the anus. These two are what make up a long, tubular intestine more commonly referred to as the large bowel.

Any abnormal lumps or tumors of the colon and rectum appear on the inner walls of the large intestine; the medical term for benign tumors is polyps while malignant ones are called cancers. Polyps are not life threatening and do not invade any nearby tissue or spread to other parts of the body and can be easily removed during a colonoscopy procedure. However, a word of caution is that if polyps are not removed from the walls of the large intestine there is a possibility that they can become cancerous in due time.

Generally, nearly all of the cancers of the large intestine (colorectal cancer) are believed to have developed from polyps. Colon and rectal cancers invade and damage adjacent tissues and organs and spread (metastasize) to other parts of the human body to form new tumors. The spread of colon cancer to other organs of the human body is called metastasis of the colon cancer. Once colorectal cancer has metastasized cure is highly unlikely.

Colorectal cancer is rated as the third leading cause of cancer in males and the fourth leading cause of cancer in females worldwide. Statistical records show that colorectal cancer is common in the Western hemisphere while it is very rare in Asia and Africa. One relevant observation is that people who have adopted western-style diets tend to develop a higher frequency of colorectal cancer increasing.

Symptoms of Colon Cancer

Colorectal cancer symptoms normally takes many years before they become manifest. Even then, symptoms vary depending on the location of the tumor in the large bowel. Because the right colon is large, right colon cancers can grow to large sizes before they set off any symptoms. Generally, right-sided colon cancer cause iron deficiency anemia due to the slow loss of blood over a long period of time. In turn, iron deficiency anemia can cause fatigue, weakness, and shortness of breath. On the other hand, the left colon is narrower than the right colon. For this reason left-sided colorectal cancers are more likely to cause partial or complete bowel obstruction. This manifests through constipation, narrow stool, diarrhea, abdominal pains, cramps, and bloating. The presence of blood in the stool may also be a symptom of a growth near the end of the left colon or rectum.

These symptoms however are non-specific because they are the same symptoms for conditions such as irritable bowel syndrome, ulcerative colitis, Crohn's disease, diverticulosis and even peptic ulcer.

To properly diagnose colorectal cancer, a barium enema x-ray or colonoscopy needs to be performed.

In a barium enema x-ray, the patient is given an enema with white liquid containing barium before a series of x-rays are taken. The barium outlines the large intestines on the x-rays while tumors and other abnormalities appear as dark shadows.

In a colonoscopy, a doctor inserts a long, flexible viewing tube into the rectum for a closer inspection of the inside of the colon. It is considered more accurate than barium enema x-rays and can be used in detecting polyps.

Common Causes of Colon Cancer

Colorectal cancer is not contagious although some people have a higher risk of developing colorectal cancer than others. Factors that affect an individual’s risk of developing colorectal cancer include but are not limited to high fat intake, genetics, the presence of polyps in the large intestine and chronic ulcerative colitis.

People whose diets contain high amounts of fat are more prone to develop colorectal cancer since when fat is metabolized; some of the by-products can cause the formation of cancer-causing chemicals in the body. On the other hand, individuals whose diets are composed of high amounts of vegetables and fibrous foods have a lower predisposition to developing colon cancer.

Medical researchers believe that most colon cancers develop from colon polyps; consequently, the removal of benign colon polyps can help prevent colorectal cancer since over a long period of time colon polyps can develop into a malignant tumor.

The inflammation of the inner lining of the color (chronic ulcerative colitis) increases an individual’s risk of developing colon cancer if the symptom is left untreated over a long period.

Another important factor in colon cancer risk is genetics. Approximately 5% of reported colon cancers are diagnosed as hereditary wherein individuals have inherited cancer causing genes from one or both of parents. In such cases, an individual’s defective chromosomes are present in every cell in the body making them more at risk of developing colon polyps even at a young age and are at very high risk of developing not only colon cancer but of other organs as well.

Prevention of Colon Cancer

It is better to take the necessary steps to prevent colorectal cancer since it can already be in the advanced stages before it is detected. Although early detection and removal of colon polyps before they become malignant is the best way to prevent colon cancer, the following steps can significantly lower your risks.

· Include fibrous fruits and vegetables in your diet.

· Lower your fat intake by lessening your portions of red meat.

· Take calcium and multivitamin supplements daily.

· Monitor your weight by exercising regularly to maintain your proper weight level.

· Quit smoking cigarettes.

· Undergo periodic screening tests for colorectal polyps and cancer.

Remember, an ounce of prevention is worth a pound of cure.