Lower gastrointestinal (GI) barium tests are used to diagnose conditions that affect a person’s colon and rectum. The procedures are sometimes called barium enemas (enemas involve fluid put into the rectum) because a thick liquid called barium is used to highlight the region on x-rays.

Lower GI barium tests may be administered in a physician’s office or the radiology department of a hospital.  Prior to the test, the lower GI tract must be completely emptied of stool and gas. This can be accomplished in a number of ways (e.g., special diet, use of laxatives and/or enemas).

During these tests, a barium bag is connected to a tube and the barium contrast agent is slowly administered through the tube into the colon. Enough barium is administered to fill up the patient’s colon. Images are then taken of the colon.

There are two major types of lower GI barium tests:

• Single-contrast barium enema. Involves an enema using a barium compound that is administered before fluoroscopy (examination with a fluoroscope, an x-ray machine that combines an x-ray source with a fluorescent screen) or conventional x-rays of the large intestine.
  
  
• Double-contrast barium enema. Also called an air-contrast barium enema, it involves a standard barium enema followed by air insufflation into the rectum and colon. Polyps and small cancers can be detected more readily with this method. The U.S. Centers for Disease Control and Prevention (CDC) recommends that people ages 50 and older have a double-contrast barium enema test every five years as part of their colorectal cancer screening routine.
  
  

  

The images captured during a lower GI barium test are read and interpreted by a radiologist, who offers an analysis to the patient’s physician. Typically, results are ready within a week of the procedure. If abnormalities are discovered, follow-up procedure or treatments may be scheduled.

Lower gastrointestinal (GI) barium tests are used to diagnose conditions in a person’s large intestine. These include disorders that affect the colon and rectum, such as abnormal growths and polyps, ulcers, small pouches on the colon wall (diverticula) and colon cancer.

The procedures are sometimes called barium enemas, because a thick liquid called barium is inserted into the patient’s colon to help highlight the region on x-rays. Barium is a soft metallic element. The type commonly used in medical tests is the compound barium sulfate, which is usually referred to simply as barium. It is radiopaque rather than radioactive, meaning that it is not transparent to X-rays or other forms of radiation. Since radiation will not pass through barium, it shows up on x-rays as a light area, making it a type of contrast medium.

There are two types of lower GI barium tests:

• Single-contrast barium enema. Involves an enema using a barium compound that is administered before fluoroscopy (examination with a fluoroscope, an x-ray machine that combines an x-ray source with a fluorescent screen) or conventional x-rays of the large intestine.
  
  
• Double-contrast barium enema. Also called an air-contrast barium enema, it involves a standard barium enema followed by air insufflation into the rectum and colon. Polyps and small cancers can be detected more readily with this method. A double-contrast enema is more effective in revealing lesions and other problems in the large intestine (colon). It is also the type of test commonly recommended for colorectal cancer screening.

Lower GI barium tests are often performed on the same day as upper GI barium tests, which are used to diagnose problems with the esophagus, stomach and duodenum. If lower GI tests are being performed the same day as upper GI tests, the lower tests should be conducted first because barium ingested during upper GI tests can obscure details on x-rays of the large intestine.

Traditionally, lower GI barium tests have been used primarily as a means of screening for colorectal cancer. The U.S. Centers for Disease Control and Prevention (CDC) recommends that people ages 50 and older have a double-contrast barium enema test every five years as part of their colorectal cancer screening regimen. However, these tests are also used to evaluate a range of other conditions, including:

• Diverticulitis. The formation of small, harmless pouches (diverticula) in the colon.
  
  
• Crohn's disease. Inflammatory disease of the small intestine or large intestine.
  

  

• Diarrhea. Frequent, loose, watery bowel movements.
  
  
• Ulcerative colitis. Chronic inflammation of the colon that produces ulcers on its lining.
  
  
• Lower gastrointestinal bleeding.
  
  
• Intussusception. Condition in which one part of colon collapses into another causing bowel obstruction.

Prior to a lower gastrointestinal (GI) barium test, the lower GI tract must be completely emptied of stool and gas. Steps to empty the lower GI tract include:

• Minimum-residue diet. This is a diet that contains low-fiber foods, allowing only minimal solids in the intestine, such as lean meat, refined cereals, pasta and liquids. Typically patients will begin this diet two or three days before the test.
  
  
• Clear liquids only. This stricter diet may be required up to three days before testing, or the patient may be started on a minimum-residue diet and then limited to clear liquids a day or two before testing. Liquids that may be allowed include water, tea and coffee without milk or cream, juice without pulp, broth, and carbonated beverages.
  
  
• Abstention from medications. The physician may ask the patient to refrain from taking some or all medications starting 12 to 24 hours before testing.
  
  
• Fasting. Typically, fasting begins 12 hours before testing.
  
  
• Laxatives, enemas, suppositories (medications inserted into the rectum, where they melt). Any combination of these may be recommended the evening before and/or the morning of the test.
  
  

  

Typically, the patient will be instructed not to eat or drink after midnight the day before the test. Patients should tell their physician if they are allergy to barium or latex products.

Lower gastrointestinal (GI) barium tests may be administered in a physician’s office or the radiology department of a hospital. The patient does not receive anesthesia and is awake during the procedure. The patient lies down sideways, and a lubricated enema tube is inserted into the rectum. A barium bag is connected to the tube and the barium contrast agent is slowly administered through the tube into the colon. Enough barium is administered to fill up the patient’s colon.

Tests may then proceed with the patient standing, lying on a tilt table or alternating between both positions. If a tilt table is used, the patient may be strapped to the table so that it can be tilted to allow pictures from various angles. When standing behind a fluoroscope (an x-ray machine that enables direct observation by combining an x-ray source with a fluorescent screen) the patient may be asked to change positions and hold their breath while x-rays are taken. This allows different views of the colon to be captured. The abdomen may be compressed by a belt or the examiner’s hand during testing. Patients may also be asked to hold their breath several times during testing.

Patients may experience some discomfort during the test. The barium may feel cool as it enters the colon and tends to cause a sensation of fullness and pressure in the abdomen. Moderate cramping may ensue, and patients may feel like a bowel movement is impending. However, this rarely occurs, as the tube used to inject the barium has a balloon on the end that is inflated to prevent the liquid from coming back out. Taking long, deep breaths may help the patient relax during this discomfort.

Once enough images have been taken, the tube is removed and the patient uses a bedpan or toilet to begin expelling the barium. In some cases, additional images may be taken after the colon has been emptied.

When a double-contrast barium enema is used, the entire process is repeated. In the second procedure, air is supplied through the enema tube along with the barium. The air helps outline the colon better for enhanced viewing by the physician and helps reveal the presence of small abnormalities.

It is not unusual for patients to experience anal soreness during the procedure, or to have to endure the unpleasant experience of having the barium leak onto themselves or the X-ray table. For many people, this is embarrassing, but patients should feel reassured that such feelings are natural and that the health professionals who administer the test are used to this and can help patients cope with such difficult situations.

Patients may have a brief recovery period immediately following the procedure. In most cases, they are able to return home shortly after the procedure. Many patients find the test to be tiring, and it may be best to have a friend or relative drive the patient home following the procedure.

Patients who undergo lower gastrointestinal (GI) barium testing may experience unpleasant soreness in the anal area. This can be relieved with warm sitz baths (in which only the pelvic area of the body is immersed) or a local anesthetic salve that is recommended by their physician.

The barium may cause constipation and make the patient’s stool turn gray or white for a few days after the procedure. Patients may receive a cleansing enema or be asked to take a laxative that will help flush the remaining barium. They may be urged to drink extra fluids for several days following the procedure.

Patients should contact their physician if they discover that their stool is not a normal color after two or three days, or if they are unable to have a bowel movement or pass gas more than two days after the exam. These may be indicators that barium remains in the colon.

The images captured during a lower GI barium test will be read and interpreted by a radiologist, who will then offer an analysis to the patient’s physician. If no colon abnormalities are discovered, the test is considered to be negative. A positive test indicates that an abnormality was found. The physician will discuss the findings with the patient. Typically, results are ready within a week of the procedure.

In most cases, barium x-rays are administered with no difficulty or lasting complications. However, risks of lower barium x-rays may include:

• Constipation. Often patients will be advised to expel the barium and avoid constipation by eating high-fiber foods, using laxatives or drinking more water.
  
  
• Radiation. Fluoroscopy and cineradiography can emit more radiation than standard x-rays.
  
  
• Hypoglycemia (low blood sugar). The fasting usually required for most types of barium x-rays can cause low glucose (blood sugar). The physician may issue special instructions for patients with diabetes and other disorders that may be affected by low glucose levels.
  
  
• Infection. In rare cases, the lining of the abdominal cavity may become infected, a condition known as peritonitis. A common symptom of infection is fever. Infection should be treated promptly.
  
  
• Cramping. This is common during both types of barium enemas, but eases after the procedure.
  
  
• Tearing of the colon. This is a rare risk of the lower gastrointestinal (GI) tests. Surgery may be necessary if the intestine is perforated.
  
  
• Intestinal obstruction. If the barium is not defecated, it can harden in the intestine. White-colored stool is normal for up to three days after barium x-rays. The patient should notify the physician if there is no white stool, or if there are other bowel problems. Intestinal obstruction could lead to potentially fatal barium poisoning.
  
  
• Poisoning. Normally the body cannot absorb barium sulfate because this compound is not water soluble. Poisoning can occur in the rare cases in which water-soluble barium compounds are accidentally used instead of insoluble forms, or in which intestinal blockage prevents the body from expelling barium sulfate. Symptoms of barium poisoning include diarrhea, nausea and vomiting, and stomach pain. In severe cases, the body can lose so much potassium that paralysis or death can result.

Patients should inform their physician if they experience any of the following:

• Moderate to severe abdominal pain
• Moderate to severe abdominal bloating
• Constipation
• Severe diarrhea
• Inability to consume food or fluids

Lower GI barium tests may not be appropriate for everyone. For instance, they are not typically recommended for pregnant women as exposure to radiation may potentially harm a developing fetus.

A physician may order follow up tests to diagnose problems with the gastrointestinal (GI) system. Depending on symptoms, a physician may recommend one or more of the following tests of the lower GI tract:

• Digital rectal examination. Inspection of the rectum by the physician with a gloved, lubricated finger.
  
  
• Sigmoidoscopy. Use of a long, flexible lighted tube to view the rectum and lower colon.
  
  
• Colonoscopy. Use of a longer tube to view the entire colon of a lightly sedated patient.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to lower gastrointestinal (GI) barium tests:

1. Which conditions can be detected with lower GI barium tests?
   
   
2. What are the different types of lower GI barium tests?
   
   
3. How should I prepare for the test?
   
   
4. Will I be conscious during the test?
   
   
5. Should I plan on having someone drive me home from the test?
   
   
6. Is the test uncomfortable or painful?
   
   
7. Should I restrict my activities following the test? For how long?
   
   
8. What signs or symptoms indicate a medical emergency?
   
   
9. What are the risks associated with the test?
   
   
10. How long will I have to wait for test results?