During an upper gastrointestinal series, a patient stands or sits in front of an X-ray machine and swallows barium, says the National Institute of Diabetes and Digestive and Kidney Diseases. The barium swallow coats the inside of the gastrointestinal tract.
If the patient is to have a double-contrast study, he also swallows crystals that create gas when they mix with the barium swallow, says the NIDDK. The gas expands the patient's stomach and allows the radiologist to see finer details of the upper GI tract. The patient doesn't need anesthesia during the procedure, and it can be done at an outpatient clinic as well as a hospital.
After the barium is swallowed, the radiologist watches the barium as it progresses through the GI tract on the X-ray and fluoroscopy, says the NIDDK. The procedure typically takes about two hours but may take longer if the barium moves more slowly through the small intestine. During this time, the radiologist might press on the patient's abdomen or have him shift positions to make sure that the barium coats the GI tract thoroughly.
After the upper GI series, the patient may experience nausea and some bloating but is able to go home soon after the procedure, states the NIDDK. Individuals can also expect to have pale stools for a few days after the procedure. Upon discharge, a patient receives detailed instructions on how to cleanse the barium leftover from the gastrointestinal tract.