For the great majority of people, the major factor that increases a person's risk for colorectal cancer (CRC) is increasing age. Risk increases dramatically after age 50 years; 90% of all CRCs are diagnosed after this age. The history of CRC in a first-degree relative, especially if before the age of 55 years, roughly doubles the risk. Other risk factors are weaker than age and family history. People with inflammatory bowel disease have a much higher risk of CRC. A small percentage (<5%) of CRCs...
Anemia: a condition in which a person has a low red blood cell count. It occurs when there is not enough hemoglobin in a person's blood. Hemoglobin is the substance in the red blood cells that enables the blood to transport oxygen throughout the body.
Antibodies: proteins produced by the body to protect itself from foreign substances, such as bacteria or viruses.
Antigens: substances that provoke an immune response in the body. The body produces antibodies to fight antigens, or harmful substances, to try to eliminate them.
Anti-inflammatory: medication used to reduce pain, swelling, or other irritation caused by inflammation.
Air contrast barium enema: also called double contrast barium enema -- an X-ray examination of the entire large intestine (colon) and rectum in which barium and air are introduced gradually into the colon by a rectal tube.
Anal fissure: a split or crack in the lining of the anal opening, usually caused by the passage of very hard or watery stools.
Anastomosis: a surgical joining of two ducts, blood vessels, or bowel segments to allow flow from one to the other.
Aneurysm: the abnormal enlargement or bulging of a blood vessel, caused by damage or weakness in the blood vessel wall.