Several different tests are used to detect gastrointestinal carcinoid cancer:

• Physical exam and history 
• Blood chemistry studies 
• Urine test 
• 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.
• 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.
• 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 with a small camera is inserted through the rectum into the large intestine to provide physicians with a view of the gastrointestinal tract.
• 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.
• ERCP (endoscopic retrograde cholangiopancreatography) This procedure is an X-ray examination of the gastrointestinal tract which is aided by a video endoscope. Through the endoscope, the physician can see the inside of the affected area. Dye is injected so the gastrointestinal tract can be better visualized to determine if there is a blockage or other abnormality.
• Biopsy Tissue samples are examined under the microscope to determine what types of cells are present.