Mild constipation from the barium enema is the most common complication of a lower GI series. Rarely, a barium enema causes bowel obstruction, a life-threatening condition that blocks the intestines. Drinking plenty of liquids after a lower GI series flushes out the barium and reduces the risks of constipation and bowel obstruction.
A 1 to 4 percent risk of acute kidney injury exists from sodium phosphate—a commonly used laxative for lower GI series bowel preps.1 Laxatives can also lead to temporary but potentially serious imbalances in electrolytes—salts and minerals in the body—possibly causing sluggishness, confusion, muscle cramps, and seizures. People with—or those at risk for—kidney disease should discuss options for minimizing bowel prep-related risks with their doctor.
Rarely, barium liquid causes an allergic reaction, which is treated with antihistamines.
Leakage of barium liquid into the abdomen through a tear in the lining of the large intestine is a rare but serious complication that usually requires emergency surgery to repair.
The risk of radiation-related damage to cells or tissues from a lower GI series is low. People who have recently undergone other x-ray tests should talk with their doctor about potential risks.