The colon is also known as the large intestine. It is the last part of the digestive tract. Colon cancer is also known as colorectal cancer. Although colon cancer can happen at any age, it usually occurs in older adults. The exact cause or causes of colon cancer are not known.
Colon cancer starts with forming non-cancerous or benign clumps of cells in the colon known as polyps. Over time, these polyps can become colon cancer. There may be no symptoms or only a few symptoms when polyps form, making them hard to detect. Regular colon cancer screening is recommended for ages 45 to 75 by the U.S. Preventive Services Task Force.
People who have colon cancer experience no symptoms during the early part of the disease. Later on, the symptoms experienced will depend on both cancer’s size and its location in the large intestine. Symptoms include changes in bowel movement such as diarrhea, constipation, persistent abdominal cramps, and stomach pain. Another symptom is blood in the stool or rectum. People with colon cancer might feel weak or tired all the time. They might also experience unexplained weight loss.
Most people who get colon cancer are over 50, although there is a recent increase in colon cancer for younger people. African-Americans have also been known to have a greater risk for colon cancer. A family history of colon cancer, previous intestinal diseases such as Crohn’s disease, and previous medical conditions involving benign polyps can increase the risk of colon cancer. Other risk factors involved being obese, a low-fiber, high-fat diet, diabetes, and smoking.
The risk factors for colon cancer point to the ideal lifestyle to lower the risk of colon cancer occurrence. This would include exercising daily and maintaining the proper weight. It is recommended to quit smoking and to drink alcohol in moderation. A person should also eat many high-fiber foods such as fruits, vegetables, and whole grains.
Various colon cancer screening tests include stool tests, flexible sigmoidoscopy, colonoscopy, and CT colonography. If the tests such as the stool tests, flexible sigmoidoscopy, and CT colonography results in a positive outcome, meaning that tumors have been detected, a colonoscopy is required to complete the screening.
Stool tests may come in guaiac-based fecal occult blood test (gFOBT), fecal immunochemical test (FIT), and FIT-DNA test. The gFOBT is done once a year and comes in the form of a test kit. This test kit uses chemicals to detect blood in the stool. FIT is also done once a year and uses antibodies to detect blood in the stool. FIT-DNA is done once every three years and detects blood and altered DNA in the stool.
Flexible sigmoidoscopy involves a visual check of the colon and rectum. This is done by inserting a flexible, thin, and lighted tube into the rectum to check for polyps. This type of test is recommended at five-year intervals. Meanwhile, CT colonography uses x-rays of the entire colon to detect abnormalities. This test is also recommended at five-year intervals.
A colonoscopy is a more comprehensive form of flexible sigmoidoscopy. A doctor also uses the thin, lighted tube to inspect the colon and rectum visually. Unlike a flexible sigmoidoscopy, the inspection involves the entire colon, whereas flexible sigmoidoscopy only scans the lower colon. A colonoscopy is recommended at 10-year intervals.
