Unusual Cancers of Childhood (PDQ®): Treatment - Patient Information [NCI] - Unusual Cancers of the Abdomen
Other conditions that are not colorectal cancer may cause these same signs and symptoms.
Tests to diagnose and stage colorectal cancer may include the following:
- Physical exam and history.
- X-ray of the chest.
- CT scan.
- PET scan.
- Bone scan.
Other tests used to diagnose colorectal cancer include the following:
- Colonoscopy: A procedure to look inside the rectum and colon for polyps, abnormal areas, or cancer. A colonoscope is inserted through the rectum into the colon. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
- Barium enema: A series of x-rays of the lower gastrointestinal tract. A liquid that contains barium (a silver-white metallic compound) is put into the rectum. The barium coats the lower gastrointestinal tract and x-rays are taken. This procedure is also called a lower GI series.
- Fecal occult blood test: A test to check stool (solid waste) for blood that can only be seen with a microscope. Small samples of stool are placed on special cards and returned to the doctor or laboratory for testing.
- Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
- The number of red blood cells, white blood cells, and platelets.
- The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
- The portion of the blood sample made up of red blood cells.
- Kidney function test: A test in which blood or urine samples are checked for the amounts of certain substances released by the kidneys. A higher or lower than normal amount of a substance can be a sign that the kidneys are not working the way they should. This is also called a renal function test.
- Liver function test: A blood test to measure the blood levels of certain substances released by the liver. A high or low level of certain substances can be a sign of liver disease.
- Carcinoembryonic antigen (CEA) assay: A test that measures the level of CEA in the blood. CEA is released into the bloodstream from both cancer cells and normal cells. When found in higher than normal amounts, it can be a sign of colon cancer or other conditions.