The colon is the part of the digestive system where the waste material is stored. The rectum is the end of the colon adjacent to the anus. Together, they form a long, muscular tube called the large intestine (also known as the large bowel). Tumors of the colon and rectum are growths arising from the inner wall of the large intestine. Benign tumors of the large intestine are called polyps. Malignant tumors of the large intestine are called cancers. Benign polyps do not invade nearby tissue or spread to other parts of the body. Benign polyps can be easily removed during colonoscopy and are not life-threatening. If benign polyps are not removed from the large intestine, they can become malignant (cancerous) over time.

Colon cancer is the term commonly used to describe colo-rectal (or bowel) cancer. The colon is part of the intestines. These consist of the small intestine (the section between the stomach and the appendix) and the large intestine (from the appendix to the anus). The large intestine is divided into the long colon and a short rectum, just before the anus. Two thirds of these cancers occur in the colon and one third in the rectum, with very few in the small intestine.

The human colon is a muscular, tube-shaped organ measuring about 4 feet long. It extends from the end of your small bowel to your anus, twisting and turning through your abdomen (belly). Colon cancer is cancer of the large intestine (colon), the lower part of your digestive system. Rectal cancer is cancer of the last 6 inches of the colon. Together, they're often referred to as colorectal cancers. About 112,000 people are diagnosed with colon cancer annually, and about 41,000 new cases of rectal cancer are diagnosed each year, according to the American Cancer Society.

Constipation, having a bowel movement less than three times a week, can be your body's way of suggesting that you make some minor adjustments in diet or exercise. However, constipation can also be a symptom of a colon cancer. In the beginning of the colon, waste material is slushy and can easily maneuver around anything that gets in its way. But as it nears the end of the colon, stool solidifies and is less forgiving of obstacles.

The impact of environment on colon cancer risk isn't very clear. But, you can use what exists to make informed health decisions. For example, if you're an American asbestos employee who works the late shift and lives in a house of smokers, well, you might want to make colon cancer screening a priority. Few people will actually fit that description, but you get the idea. If you think you're in an environment that may increase your risk of developing colon cancer, please talk to your doctor about it.

Abdominal Pain: Swelling and pain of the abdomen are also symptoms of colon cancer. This usually occurs when the intestine is blocked by a tumor. If the tumor grows large, then nausea and vomiting can occur.

Blood in your stool may be a sign of cancer, but it can also indicate other conditions. Bright red blood you notice on bathroom tissue more commonly comes from hemorrhoids or minor tears (fissures) in your anus, for example. In addition, certain foods, such as beets or red licorice, can turn your stools red. Iron supplements and some anti-diarrheal medications may make stools black. Still, it's best to have any sign of blood or change in your stools checked promptly by your doctor because it can be a sign of something more serious