There are many methods for diagnosing colon cancer. Some of these procedures are also used as screening devices to detect colon cancers in the early stages, when treatment is more successful.
Fecal Occult Blood Test (FOBT): A stool sample is examined for traces of blood not visible to the naked eye. If you do see blood in your stool, contact your doctor immediately.
Fecal Immunochemical Test (FIT): FIT is a take-home test that detects blood proteins in stool. A small, long-handled brush is used to collect a stool sample, which is placed on a test card and sent to a lab for examination.
Sigmoidoscopy: A tiny camera with flexible plastic tubing is inserted into the rectum, providing a view of the rectum and lower colon. This procedure can also be used to remove suspicious tissue for examination.
Colonoscopy: A colonoscope is a longer version of a sigmoidoscope, and can examine the entire colon. Patients must be sedated for a colonoscopy.
Double Contrast Barium Enema (DCBE): Barium is a chemical that allows the bowel lining to show up on X-ray. A barium solution is administered by enema; then the patient undergoes a series of X-rays.
Digital Rectal Exam: The doctor inserts a gloved finger into the rectum to feel for polyps or other irregularities.
Carcinoembryonic Antigen (CEA): A blood test that determines the presence of CEA, a substance, or tumor marker, produced by some cancerous tumors. This test can also be used to measure tumor growth or assess if cancer has recurred after treatment.
Stage 0: The cancer is found only in the innermost lining of the colon or rectum. Carcinoma in situ is another name for Stage 0 colorectal cancer.
Stage I: The tumor has grown into the inner wall of the colon or rectum. The tumor has not grown through the wall.
Stage II: The tumor extends more deeply into or through the wall of the colon or rectum. It may have invaded nearby tissue, but cancer cells have not spread to the lymph nodes.
Stage IIA: Cancer has spread beyond the middle tissue layers of the colon or rectum wall or has spread to nearby tissues around the colon or rectum
Stage IIB: Cancer has spread beyond the colon or rectum wall into nearby organs and/or through the peritoneum
Stage III: The cancer has spread to nearby lymph nodes, but not to other part of the body.
Stage IV: The cancer has spread to other parts of the body, such as the liver or lungs.