Several different tests are used to detect small intestine cancer:

• Physical exam and history 
• Blood chemistry studies 
• Gastrointestinal X-ray (also called an upper GI series) For this examination, the patient drinks a liquid containing barium, which makes the gastrointestinal tract easier to see in the X-ray.
• Barium enema A series of X-rays of the lower gastrointestinal (GI) tract.
• CT or CAT (computerized axial tomography) scan This procedure uses a computer connected to an X-ray machine to obtain detailed pictures of areas inside the body. A dye may be used to help visualize organs or tissues more clearly.
• PET (positron emission tomography) scan This scan is used to identify malignant cells even before an actual “lump or bump” can be detected in a physical exam, or on CAT or MRI scans. A small amount of radionuclide glucose (sugar) is injected into a vein. Because cancer cells divide more frequently than normal cells, they take up more glucose than normal cells and appear brighter in the scan.
• MRI (magnetic resonance imaging) MRI creates a series of detailed pictures of areas inside the body, using the combination of a powerful magnet, radio waves and computer imaging.
• Gastrointestinal endoscopy A thin, lighted tube called an endoscope is inserted into the body. The device emits ultrasound waves that create images of internal organs and structures.
• Colonoscope A thin, lighted tube is inserted through the rectum into the large intestine.
• Biopsy Tissue samples are examined under the microscope to determine what types of cells are present.