If screening tests find an abnormality, the health care provider will perform a physical exam and evaluate the person's personal and family medical history. Additional diagnostic tests may be ordered. These may include x-rays of the gastrointestinal tract, sigmoidoscopy, or most often, colonoscopy. The health care provider may also order a blood test called a CEA assay to measure carcinoembryonic antigen, a protein that is sometimes present in higher levels in patients with colorectal cancer.
If an abnormal area is found during a colonoscopy, a biopsy is performed to determine if cancer is present. If an abnormal area is found during a sigmoidoscopy, a biopsy may be performed during the test, and a colonoscopy may be recommended.
The National Cancer Institute's booklet What You Need to Know About Cancer of the Colon and Rectum provides more information about the diagnosis and treatment of colorectal cancer. This publication and other resources are available from the NCI Publications Locator at http://www.cancer.gov/publications on the Internet, or by calling the Cancer Information Service (CIS) toll-free at 1-800-4-CANCER (1-800-422-6237). For additional information about colorectal cancer, visit the NCI online.



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