There are two primary kinds of barium x-rays:

• Upper GI barium tests. There are four primary types of upper GI tests:
  
  
• Upper GI barium x-ray. This term is generally used to refer to a liquid barium x-ray of the stomach along with the esophagus (tube connecting the mouth to the stomach), duodenum (upper part of the small intestine) or both.
  
  It has also been used to describe a liquid barium x-ray of the esophagus only (esophagram). The esophageal wall is normally smooth, but a barium swallow can help reveal any potentially cancerous bumps that are present. A barium swallow is often the first test recommended for patients who are having trouble swallowing (dysphagia). This condition is a main symptom of  esophageal cancer and can be associated with cancers of the head, neck and oral cavity. Dysphagia may result from chemotherapy and radiation treatments as well. Barium swallows can also highlight tracheoesophageal fistulas, holes created when tumors destroy the tissue between the esophagus and the trachea (windpipe).
  
  A radiologist conducts this test to look for physical or functional problems in the upper digestive tract.
  
  
• Modified barium swallow (MBS).  This term generally refers to barium testing of the uppermost parts of the digestive tract including the mouth, pharynx, larynx and esophagus. The test also may be called a videofluoroscopic swallow study (VFSS). In this test, barium can be presented in a liquid form or in a paste that can be mixed with foods, such as pudding. In some instances, the barium used to coat a cookie prior to eating. This test is most often used with geriatric individuals, people with Parkinson’s disease, stroke patients or people with other neurological disorders. MBS is used to diagnose dysphagia and aspiration (food or liquids that enter the  airway and lungs) - common concerns among these populations. An MBS also may be used to evaluate swallowing problems as the result of certain cancers or cancer treatments.
  
  
• Barium meal (also called a barium beefsteak meal). This term generally refers to a test in which the patient digests food containing or coated with barium. The test determines whether the stomach can adequately process food. The term “barium meal” also may refer to a liquid test assessing the esophagus, stomach and/or duodenum.
  
  
• Small-bowel series. This term refers to a liquid barium x-ray of the small intestine. A small-bowel series is often done after a barium swallow assessing the esophagus and stomach.
  
  
• Lower GI barium tests. There are two types of lower gastrointestinal barium tests (lower GI series):
  
  
• Single-contrast barium enema (commonly referred to simply as a barium enema). An enema is the administration of a substance, such as barium, into the patient’s rectum through a tube. In a barium enema, a barium compound can be administered before a conventional x-ray of the large intestine. It may also be used with a fluoroscopy, an x-ray method that highlights internal structures as shadowy images on a fluorescent screen.
  
  
• Double-contrast barium enema. X-rays are taken after barium is administered into the patient’s rectum through a tube. The barium helps the x-rays outline the colon and rectum better and helps reveal abnormalities such as polyps. The night before the test, patients take a laxative and a regular enema is completed the morning of the test. Air is puffed into the rectum to enlarge the bowel.  A double-contrast enema is effective in revealing problems in the large intestine. However, research has shown that it sometimes fails to detect small polyps.
  
  The double-contrast technique may be used to diagnose stomach cancer. In this procedure, the patient swallows a thin tube and air is pumped into the stomach. This thins out the barium coating, allowing even small abnormalities to be revealed.