How is Lower GI Series done?

A lower GI series is conducted by a radiology technologist or a radiologist—a doctor who specializes in x-ray imaging—at a hospital or outpatient center.

While the patient lies on an x-ray table, a lubricated tube is inserted into the anus and the large intestine is filled with barium liquid. Patients may experience some discomfort and will feel the urge to have a bowel movement. Leakage of barium liquid is prevented by an inflated balloon on the end of the tube. To evenly coat the inside of the large intestine with barium liquid, patients are asked to change positions several times.

X-ray pictures and possibly x-ray video are taken while patients hold still in various positions, allowing the technologist or radiologist to see the large intestine at different angles. If a technologist conducts the lower GI series, a radiologist will later examine the images to look for problems.

When the imaging is complete, the balloon on the tube is deflated and most of the barium liquid drains through the tube. The patient expels the remaining barium liquid into a bed pan or nearby toilet. An enema may be used to flush out the remaining barium liquid. The entire procedure takes 30 to 60 minutes—longer if it includes a double contrast study.

What is a double contrast study?

The double contrast study gets its name from the combination of air and barium liquid working together to create a more detailed view of the intestinal lining on x rays. If performed, a double contrast study takes place after the patient has expelled most of the barium liquid. What remains clings to the intestinal wall. The large intestine is inflated with air, expanding the barium-coated large intestine, and additional x rays are taken.