The early symptoms of colon cancer are different depending on the type of growth and location of the tumor.
Mass colon cancer is slow-growing and usually has no clinical symptoms in the early stages; ulcerated colon cancer has early ulcers and usually has bleeding and infection in the early stages; some tumors grow around the intestinal wall and usually have symptoms of intestinal obstruction.
There are two types of colon cancer: left-sided colon cancer and right-sided colon cancer. Left-sided colon cancer has a larger intestinal cavity and is usually characterized by abdominal pain, changes in stool patterns, and anemia and weight loss; right-sided colon cancer has a thin intestinal cavity and is usually characterized by obstruction.