This condition is the formation of cancerous growths in the colon (colon cancer) and in the rectum (rectal cancer). These growths may be benign or malignant.
The exact cause of colorectal cancer is not known. In most cases, these cancers begin in clumps of tissue called polyps. Polyps grow from the intestinal walls. Over time, cells in the polyps can mutate and become cancerous.
Risk factors include increased age, obesity, diabetes, and a family or personal history of the disease. Lack of physical exercise, a low-fiber/high-fat diet, smoking and alcohol use can increase a person's risk. People who have certain genetic mutations and those who have an African-American ethnicity are also at a higher risk for the disease.
Symptoms may include diarrhea or constipation, blood in the stool, lower abdominal pain, and unexplained weight loss. However, some patients may show no symptoms.
Screening and Diagnosis
Colorectal cancer is usually detected with a regular screening. A physician can discuss screening options. Colorectal cancer is often diagnosed with a colonoscopy. During this procedure, a physician uses a small camera to inspect the walls of the rectum and the colon.
Small cancers contained within a polyp may be removed during colonoscopy. Larger cancers will need to be removed surgically. The type and extent of the surgery will depend on the extent of the cancer. For more advanced cancers, part of the colon may need to be removed. Chemotherapy and radiation therapy may also be needed after surgery.