When a doctor tells you they're sending you to radiology for a lower g.i. test, what does the test consist of? (aside from ct, xray, mri imaging)

X-rays plus contrast: A "lower GI" study in the Radiology department usually means a study where they put some contrast material such as barium up the rectum, and then take several x-rays to see how the colon (large intestine) looks on x-rays. Afterwards, the patient poops out the contrast material. It's usually a simple, routine x-ray procedure.