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Doctors use many tests to diagnose cancer and find out if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:
- Age and medical condition
- Type of cancer suspected
- Severity of symptoms
- Previous test results
In addition to a physical examination, the following tests may be used to diagnose small bowel cancer:
Blood tests. A blood sample may be tested for liver disease, which can be caused by small bowel cancer. Blood may also be tested for high levels of certain proteins, which can indicate that a cancer is aggressive or has spread to other parts of the body. A test of the number of red blood cells in the blood can indicate whether the cancer is causing any bleeding.
Fecal occult blood test. This test detects occult (hidden) blood in the stool, which can be caused by small bowel cancer. A small amount of stool is placed on a plastic slide or special paper and tested in the doctor's office or a laboratory.
X-ray. An x-ray is way to create a picture of the structures inside of the body using a small amount of radiation. It can help the doctor find a tumor. For small bowel cancer, x-rays may be taken of the entire gastrointestinal system, including the esophagus, stomach, small bowel, large intestine, and rectum. Sometimes, the person will drink a substance called barium, which outlines the esophagus, stomach, and small bowel on the x-ray and helps the doctor see tumors or other abnormal areas. This is called an upper gastrointestinal series with small bowel follow-through (UGI SBFT). To get a better picture of the lower gastrointestinal tract, a barium enema may be performed. In this procedure, barium is placed into the rectum and coats the rectum and large intestine. Abdominal x-rays may also show the location of a tumor.
Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. The sample removed from the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease).
Endoscopy. A test called an endoscopy allows the doctor to see the inside much of the gastrointestinal system. The person may be sedated while the doctor inserts a thin, lighted, flexible tube called an endoscope through the mouth, down the esophagus, and into the stomach and small bowel. If abnormal areas are found, the doctor can remove a sample of tissue and check it for evidence of cancer. Sometimes, the small bowel cannot be seen entirely using this traditional method of endoscopy, so the doctor may instead recommend videocapsule endoscopy (VCE). In this method, the patient swallows a small (pill-sized) capsule that contains a tiny camera and light. Pictures are collected from the capsule as it travels through the patient’s gastrointestinal system. The capsule exits the body during the patient’s next bowel movement.
Colonoscopy. A colonoscopy is similar to the traditional endoscopy described above, except that the endoscope enters the body through the anus and rectum into the colon and lower part of the small bowel.
Computed tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein to provide better detail. A CT scan can check for the spread of cancer to the lungs, liver, and other organs.
Positron emission tomography (PET) scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient’s body. This substance is absorbed mainly by organs and tissues that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body.
Laparotomy. In this procedure, a surgical incision is made in the abdomen to check for disease. Sometimes, tissue samples are taken and, often, surgery is performed at the same time to remove the tumor.
Learn more about what to expect when having common tests, procedures, and scans.
After these diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer; this is called staging. Learn more about the first steps to take after a diagnosis of cancer.