The colon is the also known as the large intestine. The large intestine is a long tube-like organ near the end of the digestive system. There are four sections of the colon: the ascending colon, transverse colon, descending colon, and sigmoid colon.
As part of the digestive system, the ascending colon receives the food you eat from the small intestine, and it travels upward, across the body (traverse colon), downward (descending colon), and towards the rectum (sigmoid colon). As the food travels, the colon removes water, nutrients, and electrolytes from the partially digested food. The remaining material continues to the rectum. The rectum is the last part of the digestive system where stool, the body’s waste product, is expelled through the anus.
Together the colon and the rectum are under the umbrella of colorectal cancer.
Colon cancer is a malignancy, abnormal cells, that begin in the colon or large intestine. Rectal cancer is cancer that affects the rectum. Colorectal cancer (CRC) includes cancers that affect the colon and the rectum. Many people use the term colon cancer to include both colon and rectal cancer.
Most colon and rectal cancers begin as benign (non-cancerous) polyps. These are flat or knob-like growths on the lining of the large intestine and rectum. Occasionally, the growths produce symptoms such as bleeding, constipation, or blood in the stool. Most often, however, the cells often produce no symptoms, which leads to people not knowing they have them.
The best way to detect the presence of polyps is with a procedure called a colonoscopy, which is performed in a physician’s office.
While some polyps remain benign (non-cancerous), some may become malignant (cancerous) over time. For this reason, when a physician finds polyps during a colonoscopy, they are generally removed during the procedure.
So, can you prevent polyps from forming in the first place? A family history of polyps or colon cancer may increase your chances of getting them. People who are over the age of 45 also have a higher risk of forming polyps in the colon. Lifestyle factors can also play a role in the development of these growths.
There are four main stages of colon cancer. As the disease progresses, the stages range from 0 to IV, with stages II,III, and IV having sub-classifications. Generally, the stages are:
Stage 0: Cancer has not grown past the inner layer of the colon or rectum (carcinoma in situ).
Stage I: Cancer has grown past the inner layer of the colon or rectum into other layers of the colon, but has not spread to the lymph nodes or nearby tissues.
Stage II: Cancer has grown into or through the outer layer of the colon wall, but has not spread to nearby tissues or lymph nodes.
Stage III: Cancer has spread to nearby lymph nodes, but not to other organs.
Stage IV: Cancer has spread to other organs beyond the colon, such as the liver, lungs, or others.
Learn more about the different stages here.
Anyone can develop colon cancer, but some people are at higher risk. If you have a family history of colon cancer, physicians generally recommend that you get screened at an earlier age because your risk of getting the disease may be higher. For those who have no family history of the disease, recommended screenings begin at age 45 as this is when the risk of getting colon cancer begins to increase.
Even if you are under the age of 45 and have no family history of colon cancer, if you experience symptoms including abdominal pain, blood in the stool, narrowing stools, or a change in bowel habits, you should speak to your health care provider about getting screened. Be sure to provide as much information as possible, including when the pain or discomfort started, the severity, and the frequency of any symptom you may be experiencing. You can learn more about the symptoms here.
Talk to your doctor about your family’s cancer history and your own health history to learn when you should start screening.
Information on these pages is provided for educational purposes only. Consult your physician before making any medical decisions.
References
https://www.cancer.gov/publications/dictionaries/cancer-terms/def/colon
