Colon cancer is a cancer that arises from the lower part of the intestines. It usually starts as a small benign polyp, or stub of tissue, but changes over time into cancerous malignant cells. The goal is to remove the polyps before they turn into cancer. It is recommended that everyone begin screening at age 50. Some patients should get screened sooner- like if you have a family member with colon cancer. A good rule of thumb is to get screened 10 years prior to their age at diagnosis. For instance, if your mom was diagnosed with colon cancer at age 55, your screening should start at age 45.
It is important to differentiate routine “screening” from “diagnosis.” Screening means checking individuals who have NO symptoms. This is often done at a Well Adult Exam, or Preventive Physical. Everyone should be screened for colon cancer starting at age 50. If you have any symptoms that suggest a disease, it is no longer “screening” but diagnostic, which means we are looking for an answer, or cause of the symptom.
For instance if you come to me for your annual exam, and I notice you are over 50 and have never had colon screening, we would discuss screening options. But, if you came to me because you have been having blood in your stools, then, regardless of your age, we our going to consider colon cancer as a cause of the bleeding. We would then do diagnostic exams and tests to determine the cause.
Colonoscopy is the gold standard for colon cancer screening. The night before the procedure you are given liquid or pills to “clean you out.” The next morning you are sedated (asleep) and a small camera is passed up the rectum and around the entire colon. If a polyp is seen, it is removed right then and sent to the lab. Colonoscopies used to be done only in hospitals, but now are generally done in an “Endoscopy Suite” on an outpatient basis. They are typically performed by a gastroenterologist, or GI Doctor.
Some signs and symptoms of colon cancer are blood in the stool, unexplained weight loss, changes in bowel habits, diarrhea, or constipation. Most patients do not have symptoms until the cancer is large and widespread. This is why screening before symptoms develop is so important.