Colon cancer is a disease in which malignant (cancer) cells form in the tissues of the colon, and rectal cancer is a disease in which malignant (cancer) cells form in the tissues of the rectum. The colon and rectum are part of the digestive system, which is made up of the esophagus, stomach and the small and large intestines. The first 6 feet of the large intestine are called the large bowel or colon. The last 6 inches are the rectum and the anal canal.
Possible colorectal cancer symptoms include a change in bowel habits or blood in the stool.
These and other symptoms may be caused by colorectal cancer. Other conditions may cause the same symptoms. Consult a doctor if any of the following colorectal cancer symptoms occur:
- A change in bowel habits
- Blood (either bright red or very dark) in the stool
- Diarrhea, constipation, or feeling that the bowel does not empty completely
- Stools that are narrower than usual
- Frequent gas pains, bloating, fullness, or cramps
- Weight loss for no known reason
- Feeling very tired