Colorectal cancer, sometimes called colon cancer, is a disease that affects the large intestine or large bowel, which is part of your digestive tract, but can also affect the rectum, which is the passageway that connects your colon to your anus.
The exact cause is not known, but risk factors can include diet, tobacco use, smoking and heavy alcohol use. Some people with a family history of cancer can also be at higher risk of developing the disease.