Colonand the rectum are important parts of our digestive system and together they are specified as the large bowel or lower gastrointestinal tract. Problems of our large bowel usually manifested as change of bowel habit, either too much or too little and sometimes passage of blood or mucus in the stool. Occasionally, there could be abdominal discomfort or pain but not commonly. The troubling thing is that all these symptoms referable to the large bowel are not specific to one disease or another. They just represent problems with the large bowel. It could be as benign as polyps, diverticular disease, functional disorder, inflammatory conditions or even as serious as cancer. Even more troubling is that polyps and diverticular disease are most of the time without any symptoms at all. Studies consistently show that one fifth to one fourth of normal people in the population when they reach the age of 40 to 50, they can have polyps in their colon without any noticeable symptoms or signs. One may ask, why bother for the polyps if they are benign and do no harm. The following may give you some perspectives.

Due to the accumulation of mutated DNA in the cells of the mucosa of the colon over the years of life, our colon is prone to develop small protrusions called polyps in the inner lining of the colon beyond certain age. The risk of polyp development increases with age for everyone. Problem is, if the DNA changes continue and accumulate in the colon cells, polyps can progress into early cancer and then late caner if untreated. We know that not all polyps will become cancer. Only 3 to 5 % of adenoma polyps will progress into cancer. But the real issue is that we have no clue which one polyp will and which not. As the polyps are pretty asymptomatic, we need intervention in the form of colonoscopy to get them pick up and remove, at the same time eliminating the risk of becoming cancer. Therefore colonoscopy and polyp removal is in itself both diagnostic and therapeutic and can be an effective method for prevention of colonic cancer.

Although colon cancer rate ranks as high as second in the list of all cancer, only less than half of the people who contract this cancer actually die from this disease because it is mostly treatable and curable especially when they are picked up early. The fact that a pre-cancerous state of adenoma polyps occur in the colon long before the development of truly invasive cancer makes this cancer preventable. This window of opportunity that we can leverage on does not share with many other types of cancer.

The regular guideline for colonoscopy for the purpose of screening for polyps and cancer is when people without particular risk, they should have the first colonoscopy at around 50 years of age. For those who are having higher risk such as some family members having colon cancer can have the first colonoscopy screen earlier than 50.

The procedure of colonoscopy involves putting in a 160 cm long flexible fiberoptic tube into the colon via the back passage. It can be accomplished comfortably with the injection of sedatives or anaesthetics. Polyps are commonly removed at the time of colonoscopy if found and they would be sent off for pathology investigation to confirm the different types of polyps or cancer.

To conclude, polyps are common and mostly without symptoms. Polyps need to be removed because they may progress into cancer. Screening colonoscopy is the way to go for detection and removal of polyps and it is a means to prevent colon cancer from developing.

Samuel Kwok