Five signs of colon cancer are weight loss, constipation, abdominal pain, nausea and a change in the shape or appearance of stools, according to MedicineNet. The exact symptoms produced depend on the location of the tumor within different parts of the colon.
Colon cancers that affect the right side of the colon cause iron-deficiency anemia, notes MedicineNet. This develops from a gradual loss of blood and is characterized by symptoms of fatigue, shortness of breath or a general feeling of malaise. Tumors located at the end of the colon also contribute to blood loss, which is added to stools during bowel movements.
Colon cancers that affect the left side of colon cause digestive problems, informs MedicineNet. Because the left-sided colon is narrower than the right, tumors that form within the narrow colon often cause the bowel to become obstructed. These tumors are characterized by symptoms that include abdominal cramping, diarrhea or persistently narrower stools.
An obstructed colon also causes symptoms of indigestion, says MedicineNet. Food that is unable to pass completely or freely backs up into the stomach. This causes symptoms of bloating or even vomiting. An obstruction that causes poor absorption of dietary nutrients contributes to weight loss, adds Today.