Barium X-ray examinations are procedures used to detect and follow the progress of some disorders of the gastrointestinal tract.
Because barium (a metallic element) is opaque to X-rays, it is used to outline organs, such as the stomach, which are not normally visible on an X-ray image.
Barium sulphate mixed with water is passed into the part of the tract requiring examination before X-rays are taken.
In some cases, barium X-ray examinations can be used as an alternative to endoscopy (internal examination using a rigid or flexible viewing tube), although endoscopy is often the preferred form of investigation.
Barium X-rays may be single- or double- contrast. Single-contrast X-rays use barium sulphate alone. The barium fills the section of the tract under examination and provides an outline image that shows up any prominent abnormalities. In double-contrast barium X-rays, the barium forms a thin film over the inner surface of the tract and the tract is subsequently filled with air so that any small surface abnormalities can be seen.
Types of examination
Various types of barium X-ray examination are used to investigate different parts of the gastrointestinal tract.
A barium swallow involves drinking a solution of barium; this procedure is used to investigate the swallowing mechanism or the oesophagus.
A barium meal is carried out to look at the lower oesophagus, stomach, and duodenum.
A barium follow-through examination can be used to investigate disorders of the small intestine; after barium has been swallowed, a series of X-rays are taken at intervals as the barium travels down the oesophagus to the intestine.
A barium enema can be used to investigate disorders of the large intestine and the rectum; the barium is introduced into the body through a tube inserted in the rectum. Any barium that remains in the intestine may be a cause of constipation.
For this reason, it is important to ensure that a patient has a high-fibre diet and drinks plenty of water following a barium examination, until all the barium has passed through.