Small Bowel Cancer: Diagnosis

Approved by the Cancer.Net Editorial Board, 04/2022

ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of the medical problem. Use the menu to see other pages.

Doctors use many tests to find, or diagnose, cancer. They also do tests to learn if cancer has spread to another part of the body from where it started. If cancer has spread, it is called metastasis. Doctors may also do tests to learn which treatments could work best.

For most types of cancer, a biopsy is the only sure way for the doctor to know if an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.

How small bowel adenocarcinoma is diagnosed

There are many tests used for diagnosing small bowel cancer. Not all tests described here will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • The type of cancer suspected

  • Your signs and symptoms

  • Your age and general health

  • The results of earlier medical tests

In addition to a physical examination, the following tests may be used to diagnose small bowel cancer:

  • Blood tests. A test of the number of red blood cells in the blood can indicate whether the cancer is causing any bleeding. Tests for your liver and kidney function may also be performed. The results will determine if either of those organs may be affected by the cancer and find out how healthy those organs are before having treatment for small bowel cancer.

  • 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. A pathologist then analyzes the sample(s). A pathologist is 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 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. Sedation is giving medication to become more relaxed, calm, or sleepy. If abnormal areas are found, the doctor can remove a sample of tissue and check it for evidence of cancer. An endoscopy allows the doctor to see some, but not all, of the small bowel. Because of this, the doctor usually recommends a 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 takes pictures of the inside of the body using x-rays taken from different angles. A computer combines these pictures into a detailed, 3-dimensional or 3D image that shows any abnormalities or tumors. A CT scan can be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow. A CT scan can check for the spread of cancer to the lungs, liver, and other organs.

  • Positron emission tomography (PET) or PET-CT scan. A PET scan is usually combined with a CT scan (see above), called a PET-CT scan. However, you may hear your doctor refer to this procedure just as a PET scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive sugar substance is injected into the patient’s body. This sugar substance is taken up by cells that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. However, the amount of radiation in the substance is too low to be harmful. 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.

  • Biomarker testing of the tumor. Your doctor may recommend running laboratory tests on a tumor sample to identify specific genes, proteins, and other factors unique to the tumor. This may also be called molecular testing of the tumor. Results of these tests can help determine whether immunotherapy may be a treatment option for metastatic disease.

After diagnostic tests are done, your doctor will review the results with you. If the diagnosis is small bowel cancer, these results also help the doctor describe the cancer. This is called staging.

The next section in this guide is Stages and Grades. It explains the system doctors use to describe the extent of the disease. Use the menu to choose a different section to read in this guide.