Because people usually experience no pain or other symptoms during the early stages of colon cancer, screening for the disease is important. You should check with your healthcare provider if you experience any possible colon cancer symptoms. Some common symptoms of colon cancer that may develop as the disease progresses include vomiting, blood in the stool, constantly feeling tired, weight loss with no known reason, and general abdominal discomfort (such as frequent gas pains, bloating, fullness, and/or cramps). Do not wait until there is pain before you see your healthcare provider. Fortunately, colon cancer is highly curable if diagnosed and treated early.