A lower gastrointestinal series is a medical procedure used to examine and diagnose problems with the human colon of the large intestine.

Radiographs (X-ray pictures) are taken while barium sulfate, a radiocontrast agent, fills the colon via an enema through the rectum.

Virtual colonoscopy also avoids the risk of total blockage of any stricture in the large bowel due to barium impaction.

If barium meal was performed recently, then it is advised to wait for another seven to ten days before repeating the procedure.

Double contrast (where air is inflated into the bowel after excess barium are drained through anus) is useful in visualising mucosal pattern.

Subject should be fasted and Picolax (sodium picosulfate) is taken orally to empty the bowels before barium enema procedure.

The barium sulfate, a radiodense (shows as white on X-ray) contrast medium, flows through the rectum into the colon.

[1] Left posterior oblique (LPO) position is to view the sigmoid colon without overlapping of other bowels.

CT scans and ultrasounds are now the tests of choice for the initial evaluation of abdominal masses, and colonoscopies are becoming the standard for routine colon screening for those over age 50 or with a familial history of polyps or colon cancer, although it is not uncommon for a barium enema to be done after a colonoscopy for further evaluation.