Colon cancer, also known as colorectal cancer, is the third most prevalent cancer in the country. The American Cancer Society reports that about 1 in 25 women and 1 in 23 men may develop colon cancer during their lifetime. It starts in the large intestines and colon, with some instances beginning in the rectum. These organs are part of the digestive system. Read on to learn more about colon cancer, including its symptoms, causes, stages, and treatment. Signs and symptoms of colon cancer Issues with bowel movement Changes in bowel movements can be a sign of colon cancer. Watery stools caused by diarrhea, sudden changes in stool consistency, constipation, or hard, dry stool with fluid leakage are potential indications. Although these symptoms may indicate digestive system problems, it is crucial to seek medical attention if they persist for an extended period. A doctor may recommend undergoing tests to detect cancerous cells in the colon. Bleeding from the rectal area Another common sign of colon cancer is rectal bleeding. The bleeding may occur in the digestive tract. As a result, the stool may appear maroon, crimson red, dark brown, or even tar-like black. But in some cases, the bleeding is not very clear.