NewYork-Presbyterian. The University Hospital of Columbia and Cornell.

How is a barium enema performed?
Usually, a barium enema can be performed on an outpatient basis. The patient may be asked to do the following in preparation for a barium enema:

• Drink clear liquids the day before the examination.
  
  
• Take a laxative, suppository, or drug to cleanse the bowel.
  
  
• Refrain from eating and drinking after midnight on the night before the examination.

These measures are done to empty the large intestine, as any residue (feces) can obscure the image.

Barium enemas are performed in two ways:

• single-contrast image - when the entire large intestine is filled with barium liquid. Single-contrast images show prominent abnormalities in the large intestine.

• double-contrast image - when a smaller quantity of thicker barium liquid is introduced to the large intestine, followed by air. Double-contrast images show smaller surface abnormalities of the large intestine, as the air prevents the barium from filling the intestine. Instead, the barium forms a film on the inner surface.

Although each hospital may have specific protocols in place, generally, a barium enema procedure follows this process:

1. The patient is positioned on an examination table.
   
   
2. A rectal tube is inserted in the rectum to allow the barium to flow into the intestine.
   
   
3. The radiologist uses a machine called a fluoroscope (a devise used for the immediate showing of an x-ray image).
   
   
4. During the procedure, the machine and examination table will move and the patient may be asked to change positions.
   
   
5. After the procedure, a small amount of barium will be expelled by the body immediately. The remainder of the liquid is later excreted in the stool. Barium liquid may cause constipation. Following the examination, the patient may be asked to eat foods high in fiber and drink plenty of fluids to help expel the barium from the body.
   
   
6. Additional x-rays may be made immediately after the procedure in order to obtain greater details of the area under examination. Often, additional x-rays are made after the barium has been excreted from the bowel, which is usually one or more days after the procedure.

How is a barium small-bowel enema performed?
Usually, a barium small-bowel enema can be performed on an outpatient basis. Patients may be asked to refrain from eating or drinking after midnight on the night before the examination. An enema or laxative may be given on the day before the test to clear feces from the colon.

Although each hospital may have specific protocols in place, generally, a barium small-bowel procedure follows this process:

1. The patient is positioned on the examination table.
   
   
2. The radiologist uses a machine called a fluoroscope (a devise used for the immediate showing of an x-ray image).
   
   
3. A small tube is inserted through the mouth or nose into the stomach and small intestine. Barium is passed through the tube to the small intestine as x-ray images are taken.
   
   
4. Following the examination, the patient may be asked to eat foods high in fiber and drink plenty of fluids to expel the barium from the body.
   
   
5. Additional x-rays may be made immediately after the procedure in order to obtain greater details of the area under examination. Often, additional x-rays are made after the barium has been excreted from the bowel, which is usually one or more days after the procedure.

How is a barium swallow performed?
Usually, a barium swallowcan be performed on an outpatient basis. Patients may be advised not to eat or drink after midnight on the night before the examination.

Although each hospital may have specific protocols in place, generally, a barium swallow procedure follows this process:

1. The patient is asked to drink the barium liquid and to swallow baking soda crystals. It is important not to belch, as the gas assists the radiologist in evaluation.
   
   
2. The patient remains standing behind a machine called a fluoroscope (a devise used for the immediate showing of an x-ray image).
   
   
3. The patient may be asked to move in different positions and to hold his/her breath while the x-rays are taken.
   
   
4. If the small intestine is to be examined, the patient may be asked to drink additional barium and a series of x-rays are taken until the barium reaches the colon.
   
   
5. Following the examination, barium may cause constipation. The patient may be advised to drink plenty of fluids and eat foods high in fiber to expel the barium from the body.