Transcription: Barium swallow. An X-ray study of the portion of the digestive canal between the throat and stomach, esophagus, in which the patient swallows a barium mixture while the radiologist watches for signs of narrowing, irregularity, or blockage. No preparation is required except fasting. Sometimes in a procedure called an upper gastrointestinal or UGI series, the barium is also observed after it enters the stomach to check for stomach problems or ulcers. you