An Overview of Diagnosing Colon Cancer
If you have any signs or
symptoms of colon cancer, your doctor must determine whether they are due to cancer or some other cause. Your doctor will ask about your personal and family medical history, and may do a physical exam.
Tests Used for Colon Cancer Diagnosis
Rectal Exam
A rectal exam is often part of a routine physical examination. The doctor or nurse inserts a lubricated, gloved finger into the lower part of the rectum to feel for abnormal areas.
Fecal Occult Blood Test (FOBT)
Sometimes cancers or polyps bleed, and the FOBT can detect tiny amounts of blood in the stool. If this test detects blood, other tests (such as a colonoscopy) are needed to find the source of the blood. Other conditions, like
hemorrhoids, can also cause blood in the stool.
Sigmoidoscopy
During a sigmoidoscopy, the doctor checks inside the rectum and lower (sigmoid)
colon with a lighted tube called a sigmoidoscope. If polyps or other unusual areas are found, the doctor may remove them or take a tissue sample (biopsy) to check for cancer cells.