Common colon cancer symptoms include changes in bowel habits like persistent diarrhea or constipation, blood in your stool (which can appear bright red or dark and tarry), abdominal pain or cramps, bloating, and unexplained weight loss. Other signs may be unexplained fatigue, weakness, or shortness of breath, which can be symptoms of anemia caused by long-term blood loss from the tumor. If you notice any of these symptoms, especially if they are persistent or unexplained, it’s crucial to consult a healthcare provider to get a proper diagnosis.