It is common to have colon or rectal cancer without symptoms. Many patients are free of symptoms until their tumors are quite advanced.
Symptoms associated with colorectal cancer may also be caused by other conditions. These symptoms include:
- Changes in bowel movements, such as diarrhea or constipation, or change in consistency or size of stools
- Feeling that the bowel has not emptied completely after a bowel movement
- Abdominal discomfort such as gas, bloating, and cramps
- Rectal bleeding or blood in stool
- Pain when having a bowel movement
- Unexplained weight loss
- Unexplained iron-deficiency anemia (low red blood cell count)
- Weakness and fatigue
Review Date: 10/21/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.