Barium x-rays can refer to a number of tests of the gastrointestinal (digestive) system. The tests examine the gastrointestinal (GI) tract, the region of the body from the esophagus to the rectum. These x-rays can detect cancers that occur in any portion of the GI tract.

Diagnostic tools that use barium x-rays are divided into two main categories:

• Upper GI tests (mouth, esophagus, stomach and small intestine), including barium swallow, barium meal and small-bowel series
  
  
• Lower GI tests (large intestine [colon and rectum]), including barium enemas (the administration of barium into the patient’s rectum through a tube)

Barium is used in radiology tests because its contrast properties outline internal organs and they appear white on the x-ray images.    It helps to visualize problem areas and can indicate difficulties with swallowing (dysphagia) or digestion, ulcerations, malignancy or structural abnormalities.