An upper gastrointestinal series (upper GI series, barium swallow) is an x-ray test used to define the anatomy of the upper digestive tract. It involves filling the esophagus, stomach, and small intestines with a white liquid material (barium).
Prior to an upper GI series, patients are requested not to eat or drink anything from four to eight hours before the procedure. Also, patients also are asked to remove extraneous clothing and all metallic objects such as jewelry. The patient then is asked to swallow a liquid that contains barium.
The barium fills and then coats the lining of the intestinal tract making the adjacent esophagus, stomach and duodenum visible. (X-rays of the stomach and intestine done without barium provide very little detail and information.)
Then, X-ray images are obtained at different angles through the chest and abdomen. The different organs and certain abnormalities and conditions all become visible on the X-ray film since they block the penetration of the X-ray beam to varying degrees.
After the development of the film, an image of the organs is revealed. The radiologist then examines the X-rays and can define various normal and abnormal structures of the gastrointestinal system.
If needed, further enhancement of the different structures can be obtained by having air as well as barium in the stomach. This is accomplished by swallowing baking soda crystals.
As barium passes through the digestive system, constipation can result, especially in patients prone to constipation. Therefore, it generally is advisable that patients who undergo an upper GI series drink extra fluids after the test and consider a laxative to relieve the bowels of the barium if the barium is not eliminated completely within the next day or two. As it is passing in the stool, barium has a whitish appearance that may be apparent for several days after the test.
The risk of an upper GI series from radiation exposure is minimized by standard techniques that have been assigned and approved by national and international radiology committees and councils. Patients who are or may be pregnant should notify the requesting practitioner and radiology staff, as there is a potential risk of harm to the fetus with any radiation exposure.
After the radiology technician develops the X-ray film or digital image, it is transferred to the radiologist physician who interprets the body images produced and generates a report that is transmitted to the physician who requested the test. The practitioner can review the results of the upper GI series with the patient and can proceed with therapy or discuss whether other tests may be necessary.