In a double-contrast barium enema, a fine coating of thick barium is
needed to outline the mucosal lining of the bowel. The patient will be
placed prone so that gravity can assist the air in distributing the liquid
around the large bowel. The patient is asked to turn over 360 degrees a few
times during the exam to aid in the coating of the bowel. The patient is
then placed upright, and more air is injected into the bowel so gravity
again can assist in visualizing the large intestine. Patients may develop
spasms of the bowel during this exam, so the radiologist may give the
patient a glucagon injection to relax the large bowel. This injection should
not be given to patients with a history of glaucoma and can cause
temporary double-vision in these patients.
The radiologist will take spot-films under fluoroscopy of each segment of
the bowel but most of the films will be made following the procedure by the
x-ray technologist. Since less barium is used along with some air, less
kilovoltage (90-100kvp) is needed to achieve a high contrast x-ray of the
large intestine. The usual AP and PA (posteroanterior) abdomen films will be
done as well as the two oblique views of the abdomen. An upright film may be
done as well depending on the routine of the radiologist. The most important
films for the double-contrast exam are the two lateral decubitus films. The
patient is placed on a large cushion or sponge and turned completely onto
one side. A stationary grid is placed next to the patient and the x-ray tube
is turned 90 degees. This film allows the air to rise to the upper surface
of the abdomen so that the air along with the thin coating of barium creates
a detailed visualization of the intestinal lining. This is extremely
important when looking for small polyps, cancers, and ulcerations of the
bowel. Films of both sides are always taken.
Double contrast barium enema equipment
