The colon, commonly called large intestine or large bowel, is the part of the digestive tract between the small intestine and rectum. It is located in the abdominal cavity. It measures average 1.5 meters long and 8 cm in diameter in adults, and divided into four segments: ascending colon, sometimes called right colon; transverse colon, running across the abdomen; descending colon, also known as left colon; and the sigmoid colon, which is thecurving part just before the rectum. The colon completes the processing of waste from the intestines into feces, which are then expelled through the rectum. This is an important organ but subject to several diseases, such as cancer.
Colon cancer develops from the mucous membrane of the colon (colonic mucosa). In 70% of cases, the tumor starts its development in the mucosa of the sigmoid colon. Cancers of the colon and rectum are quite similar; they are, therefore, grouped under the term of colorectal cancer. This is the second most common malignant tumor in women, after breast cancer, and the third in men, after lung cancer and prostate cancer. In the US alone, about 130000 people are diagnosed with the disease each year.
Among non-smokers, together colon cancer and rectal cancer are the second leading cause of cancer death. It seems that the tumor has a preference for male and certain geographical Areas. For instance, men are more victims than women, 40% and 27%, respectively; Africa and Asia inhabitants are 20 times less likely to be affected by colorectal cancers than residents in the United States, according to the International Agency for Research on Cancer (IARC).
Colon cancer tends to take several years to form, as the cases of rectal cancer. The tumor usually begins from polyps in the lining covering the inside of the colon, and spreads to other tissues or organs if it is not properly treated.
Colon polyps are small fleshy growths. Most people have them but do not know it. Most of the times, they develop and remain benign without ever becoming malignant. However, in some individuals, they may become cancerous on average 10 years. Therefore, to prevent cancer formation, as soon as a health care provider detects polyps in a patient, he conducts appropriate diagnostic procedures to determine their nature and potential health.
It is important for everyone to be familiar with symptoms indicative of polyps and take appropriate actions in case they experience them. For instance, presence of blood in the stool, persistent diarrhea or constipation, should not be ignored. It is crucial for the individual to seek advice of a medical professional, and ask him to perform necessary texts. For those at risk of colon cancer, it is advised to undergo testing.