A medical test more commonly known as a barium enema. The lower g-i series involves filling the colon with barium sulfate (which is opaque to x-rays) and sometimes air and taking x-rays to search for abnormalities. See barium enema for more detail.

Tests similar in function to the lower g-i series are colonoscopy and sigmoidoscopy, both of which examine the colon or part of the colon. Contrast with the Upper Gastro-Intestinal Series, where the stomach, duodenum, and small intestine are examined.