What is a barium enema

A barium enema is an X-ray exam (using real-time x-ray called fluoroscopy) in which a liquid that contains barium sulfate is put through the anus into the rectum and large intestine (colon) in order to detect changes or abnormalities in the large intestine. A barium enema procedure is also called a colon X-ray or lower gastrointestinal tract radiography. A barium enema can help detect disease and abnormalities and diagnose symptoms such as pain, constipation or blood in the stool. A barium enema can often provide enough information to avoid more invasive procedures such as colonoscopy.

An enema is the injection of a liquid into your rectum through a small tube. In this case, the liquid contains a metallic substance (barium) that coats the lining of the colon. Normally, an X-ray produces a poor image of soft tissues, but the barium coating results in a relatively clear silhouette of the colon.

During a barium enema exam, air may be pumped into the colon. The air expands the colon and improves the quality of images. This is called an air-contrast (double-contrast) barium enema.

Before a barium enema, your doctor will instruct you to completely empty your colon.

During the barium enema:

• you’ll be asked to lie on your side on an X-ray table, and an injection of a medication called Buscopan may be given into your arm or hand to prevent involuntary bowel movements
• a small, soft tube will be gently inserted a few centimeters into your bottom, where it will remain throughout the test
• the barium is passed through the tube and into your bowel – try to keep the muscles in your bottom tight to prevent it coming back out, but don’t worry if some leaks out
• you may be asked to move around a bit to help the barium spread along your bowel, and air may be pumped into your bowel to expand it and help push the barium around
• several X-rays will be taken with you in different positions

The whole process usually takes around 30 to 45 minutes.

Nowadays, barium enemas aren’t carried out very often, as alternative tests such as a colonoscopy or CT scan are usually preferred.

But a barium enema can sometimes be a useful way of finding the cause of problems like blood in your stools or a constant change in your bowel habits.

Conditions that can be detected during a barium enema include:

• bowel cancer
• growths in the bowel (bowel polyps)
• inflammation of the bowel (ulcerative colitis) or Crohn’s disease
• pouches in the bowel (diverticular disease)

Does a barium enema hurt?

Having a barium enema may be a bit embarrassing and unpleasant, but it shouldn’t be painful.

You’ll probably feel uncomfortable when the air is pumped into your bowel during the test, similar to the feeling of having trapped wind.

You may have some bloating, wind or stomach cramps for a short while afterwards.

What will I experience during and after the barium enema procedure?

As the barium fills your colon, you will feel the need to move your bowel. You may feel abdominal pressure or even minor cramping. Most people tolerate the mild discomfort easily. The tip of the enema tube is specially designed to help you hold in the barium. If you are having trouble, let the technologist or radiologist know.

During the imaging process, you will be asked to turn from side to side and to hold several different positions. At times, pressure may be applied to your abdomen. With air contrast studies of the bowel (air contrast barium enema), the table may be moved to an upright position.

After the examination, you may be given a laxative or enema to wash the barium out of your system. You can resume a regular diet and take orally administered medications unless told otherwise by your doctor. You may be able to return to a normal diet and activities immediately after the examination. You will be encouraged to drink additional water for 24 hours after the examination.

Your stools may appear white for a day or so as your body clears the barium liquid from your system. Some people experience constipation after a barium enema. If you do not have a bowel movement for more than two days after your exam or are unable to pass gas rectally, call your physician promptly. You may need an enema or laxative to assist in eliminating the barium.

Barium enema indications

Your doctor may recommend a barium enema to determine the cause of signs and symptoms, such as the following:

• Abdominal pain
• Rectal bleeding
• Blood in stools
• Changes in bowel habits
• Unexplained weight loss
• Chronic diarrhea
• Persistent constipation
• Irritable bowel syndrome.
• Suspected blood loss.

A barium enema X-ray may enable your doctor to detect such conditions as:

• Abnormal growths (polyps)
• Inflammatory bowel disease e.g., ulcerative colitis, Crohn’s disease
• Hirschsprung disease in children (a blockage of the large intestine).

Barium enema vs Colonoscopy

During a colonoscopy, a long, flexible tube (colonoscope) is inserted into the rectum. A tiny video camera at the tip of the tube allows the doctor to view the inside of the entire colon. If necessary, polyps or other types of abnormal tissue can be removed through the scope during a colonoscopy. Tissue samples (biopsies) can be taken during a colonoscopy as well.

Your doctor may recommend a colonoscopy to:

• Investigate intestinal signs and symptoms. A colonoscopy can help your doctor explore possible causes of abdominal pain, rectal bleeding, chronic constipation, chronic diarrhea and other intestinal problems.
• Screen for colon cancer. If you’re age 50 or older and at average risk of colon cancer — you have no colon cancer risk factors other than age — your doctor may recommend a colonoscopy every 10 years or sometimes sooner to screen for colon cancer. Colonoscopy is one option for colon cancer screening. Talk with your doctor about your options.
• Look for more polyps. If you have had polyps before, your doctor may recommend a follow-up colonoscopy to look for and remove any additional polyps. This is done to reduce your risk of colon cancer.

A colonoscopy poses few risks. Rarely, complications of a colonoscopy may include:

• Adverse reaction to the sedative used during the exam
• Bleeding from the site where a tissue sample (biopsy) was taken or a polyp or other abnormal tissue was removed
• A tear in the colon or rectum wall (perforation)

After discussing the risks of colonoscopy with you, your doctor will ask you to sign a consent form authorizing the procedure.

Colonoscopy preparation

Before a colonoscopy, you’ll need to clean out (empty) your colon. Any residue in your colon may obscure the view of your colon and rectum during the exam.

To empty your colon, your doctor may ask you to:

• Follow a special diet the day before the exam. Typically, you won’t be able to eat solid food the day before the exam. Drinks may be limited to clear liquids — plain water, tea and coffee without milk or cream, broth, and carbonated beverages. Avoid red liquids, which can be confused with blood during the colonoscopy. You may not be able to eat or drink anything after midnight the night before the exam.
• Take a laxative. Your doctor will usually recommend taking a laxative, in either pill form or liquid form. You may be instructed to take the laxative the night before your colonoscopy, or you may be asked to use the laxative both the night before and the morning of the procedure.
• Use an enema kit. In some cases, you may need to use an over-the-counter enema kit — either the night before the exam or a few hours before the exam — to empty your colon. This is generally only effective in emptying the lower colon and is usually not recommended as a primary way of emptying your colon.
• Adjust your medications. Remind your doctor of your medications at least a week before the exam — especially if you have diabetes, high blood pressure or heart problems or if you take medications or supplements that contain iron.

Also tell your doctor if you take aspirin or other medications that thin the blood, such as warfarin (Coumadin, Jantoven); newer anticoagulants, such as dabigatran (Pradaxa) or rivaroxaban (Xarelto), used to reduce risk of blot clots or stroke; or heart medications that affect platelets, such as clopidogrel (Plavix).

You may need to adjust your dosages or stop taking the medications temporarily.

During the colonoscopy procedure

During a colonoscopy, you’ll wear a gown, but likely nothing else. Sedation is usually recommended. Sometimes a mild sedative is given in pill form. In other cases, the sedative is combined with an intravenous pain medication to minimize any discomfort.

You’ll begin the exam lying on your side on the exam table, usually with your knees drawn toward your chest. The doctor will insert a colonoscope into your rectum.

The scope — which is long enough to reach the entire length of your colon — contains a light and a tube (channel) that allows the doctor to pump air or carbon dioxide into your colon. The air or carbon dioxide inflates the colon, which provides a better view of the lining of the colon.

When the scope is moved or air is introduced, you may feel abdominal cramping or the urge to have a bowel movement.

The colonoscope also contains a tiny video camera at its tip. The camera sends images to an external monitor so that the doctor can study the inside of your colon.

The doctor can also insert instruments through the channel to take tissue samples (biopsies) or remove polyps or other areas of abnormal tissue.

A colonoscopy typically takes about 30 to 60 minutes.

After the colonoscopy procedure

After the exam, it takes about an hour to begin to recover from the sedative. You’ll need someone to take you home because it can take up to a day for the full effects of the sedative to wear off. Don’t drive or make important decisions or go back to work for the rest of the day.

If your doctor removed a polyp during your colonoscopy, you may be advised to eat a special diet temporarily.

You may feel bloated or pass gas for a few hours after the exam, as you clear the air from your colon. Walking may help relieve any discomfort.

You may also notice a small amount of blood with your first bowel movement after the exam. Usually this isn’t cause for alarm. Consult your doctor if you continue to pass blood or blood clots or if you have persistent abdominal pain or a fever. While unlikely, this may occur immediately or in the first few days after the procedure, but may be delayed for up to one to two weeks.

Colonoscopy results

Your doctor will review the results of the colonoscopy and then share the results with you.

Negative result

A colonoscopy is considered negative if the doctor doesn’t find any abnormalities in the colon.

Your doctor may recommend that you have another colonoscopy:

• In 10 years, if you’re at average risk of colon cancer — you have no colon cancer risk factors other than age
• In five years, if you have a history of polyps in previous colonoscopy procedures
• In one year, if there was residual stool in the colon that prevented complete examination of your colon

Positive result

A colonoscopy is considered positive if the doctor finds any polyps or abnormal tissue in the colon.

Most polyps aren’t cancerous, but some can be precancerous. Polyps removed during colonoscopy are sent to a laboratory for analysis to determine whether they are cancerous, precancerous or noncancerous.

Depending on the size and number of polyps, you may need to follow a more rigorous surveillance schedule in the future to look for more polyps.

If your doctor finds one or two polyps less than 0.4 inch (1 centimeter) in diameter, he or she may recommend a repeat colonoscopy in five to 10 years, depending on your other risk factors for colon cancer.

Your doctor will recommend another colonoscopy sooner if you have:

• More than two polyps
• A large polyp — larger than 0.4 inch (1 centimeter)
• Polyps and also residual stool in the colon that prevents complete examination of the colon
• Polyps with certain cell characteristics that indicate a higher risk of future cancer
• Cancerous polyps

If you have a polyp or other abnormal tissue that couldn’t be removed during the colonoscopy, your doctor may recommend a repeat exam with a gastroenterologist who has special expertise in removing large polyps, or surgery.

Problems with your exam

If your doctor is concerned about the quality of the view through the scope, he or she may recommend a repeat colonoscopy or a shorter time until your next colonoscopy. If your doctor wasn’t able to advance the scope through your entire colon, a barium enema or virtual colonoscopy may be recommended to examine the rest of your colon.

Barium enema prep

To ensure the X-ray images taken during a barium enema are clear, your bowel must be empty before the test. Any residue in your colon may obscure the X-ray images or be mistaken for an abnormality.

Before a barium enema exam, you’ll be instructed to empty your colon.

To empty your colon, you may be asked to:

• Follow a special diet the day before the exam. You may be asked not to eat and to drink only clear liquids — such as water, tea or coffee without milk or cream, broth, and clear carbonated beverages.
• Drink plenty of clear fluids – this will help to replace the fluids you lose each time you empty your bowels
• Fast after midnight. Usually, you’ll be asked not to drink or eat anything after midnight before the exam.
• Take a laxative the night before the exam. A laxative, in a pill or liquid form, will help empty your colon.
• Use an enema kit. In some cases, you may need to use an over-the-counter enema kit — either the night before the exam or a few hours before the exam — that provides a cleansing solution to remove any residue in your colon.
• Ask your doctor about your medications. At least a week before your exam, talk with your doctor about the medications you normally take. He or she may ask you to stop taking them days or hours before the exam.

It’s usually a good idea to stay at home the day before the test, as the laxative medication will make you go to the toilet frequently.

Contact the hospital as soon as you receive your appointment letter if you have diabetes or are pregnant (or think you could be pregnant).

If you have diabetes, you’ll need to follow special instructions to ensure your blood sugar level is kept under control.

Barium enemas aren’t done during pregnancy because the X-rays may harm the baby.

Barium enema procedure

During your barium enema, you’ll wear a gown and be asked to remove eyewear, jewelry or removable dental devices. The exam will be performed by a radiology technician and a physician who specializes in diagnostic imaging (radiologist).

You’ll begin the exam lying on your side on a specially designed table. An X-ray will be taken to make sure your colon is clean. Then a lubricated enema tube will be inserted into your rectum. A barium bag will be connected to the tube to deliver the barium solution into your colon.

If you’re having an air-contrast (double-contrast) barium enema, air will flow through the same tube and into your rectum.

The tube that’s used to deliver the barium has a small balloon near its tip. When positioned at the entrance of your rectum, the balloon helps keep the barium inside your body. As your colon fills with barium, you may feel the urge to have a bowel movement. Abdominal cramping may occur.

Do your best to hold the enema tube in place. To relax, take long, deep breaths.

You may be asked to turn and hold various positions on the exam table. This helps ensure that your entire colon is coated with barium and enables the radiologist to view the colon from various angles. You also may be asked to hold your breath at times.

The radiologist may press firmly on your abdomen and pelvis, manipulating your colon for better viewing on a monitor attached to the X-ray machine. A number of X-rays will likely be taken of your colon from various angles.

A barium enema exam typically takes about 30 to 60 minutes.

After the  barium enema exam

After the exam, most of the barium will be removed from your colon through the enema tube. When the tube is removed, you’ll be able to use the toilet to expel additional barium and air. Any abdominal cramping usually ends quickly, and you should be able to return to your usual diet and activities right away.

You may have white stools for a few days as your body naturally removes any remaining barium from your colon. Barium may cause constipation, so you may find you can reduce your risk of constipation by drinking extra fluids in the days following your exam. Your doctor may recommend a laxative, if needed.

Check with your doctor if you’re unable to have a bowel movement or pass gas more than two days after the exam or if your stool doesn’t return to its normal color within a few days.

You should be able to go home shortly afterwards, although it’s a good idea to take things easy for a few hours before returning to your normal activities.

If you had a Buscopan injection, your vision may be blurry for 30 to 60 minutes, so you won’t be able to drive during this time. It’s best to arrange for someone to drive you home.

When you get home:

• stay close to a toilet for the next few hours, as you may find you need to empty your bowels quite often at first
• your poop may be a whitish color for a few days – this is normal and is just the remaining barium passing out of your body
• you can eat and drink as normal – drink plenty of fluids and eat high-fiber foods for the first few days to help stop the barium causing constipation

The X-ray images taken during the test will be analyzed by a specialist. A report will be sent to the doctor who referred you for the test and you can discuss the results at your next appointment.

Barium enema results

The radiologist prepares a report based on the results of the examination and sends it to your doctor. Your doctor will discuss the results with you, as well as subsequent tests or treatments that may be required:

• Negative result. A barium enema exam is considered negative if the radiologist detects no abnormalities in the colon.
• Positive result. A barium enema exam is considered positive if the radiologist detects abnormalities in the colon. Depending on the findings, you may need additional testing — such as a colonoscopy — so that any abnormalities can be examined more thoroughly, biopsied or removed.

If your doctor is concerned about the quality of your X-ray images, he or she may recommend a repeat barium enema or another type of diagnostic test.

Barium enema side effects

A barium enema is generally a very safe procedure, although there a few risks and side effects that you should be aware of.

Rarely, complications of a barium enema exam may include:

• Inflammation in tissues surrounding the colon
• Obstruction in the gastrointestinal tract
• Bowel perforation or tear in the colon wall  – there’s a risk of a small hole developing in your bowel as a result of the procedure, but this is very rare
• Allergic reaction to barium – barium is usually harmless, but it can cause an upset stomach or constipation, and can cause an allergic reaction in very rare cases
• Laxative side effects – side effects such as feeling sick, a mild headache and bloating are common, but shouldn’t last long
• Radiation exposure – you’ll be exposed to a small amount of radiation during the test; this is about the equivalent to what you would receive naturally from the environment over 3 years.

Barium enema exams generally aren’t done during pregnancy because X-rays present a risk to the developing fetus.

Your doctor can help you weigh up the risks of the procedure against the benefits of identifying any problem in your bowel.

Barium enema benefits vs. risks

Benefits of barium enema

• X-ray imaging of the lower GI tract is a minimally invasive procedure with rare complications.
• Radiology examinations such as the lower GI can often provide enough information to avoid more invasive procedures such as colonoscopy.
• Because barium is not absorbed into the blood, allergic reactions are extremely rare.
• No radiation remains in a patient’s body after an x-ray examination.
• X-rays usually have no side effects in the typical diagnostic range for this exam.

Risks of barium enema

• There is always a slight chance of cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk.
• The effective radiation dose for this procedure varies. See the Safety page for more information about radiation dose.
• In rare cases, the barium could leak through an undetected hole in the lower GI tract producing inflammation in surrounding tissues.
• Even more rarely, the barium can cause an obstruction in the gastrointestinal tract, called barium impaction.
• Iodinated contrast administered rectally may cause allergic reactions, but this is very rare.
• Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.

A word about minimizing radiation exposure

Special care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals.

Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that those parts of a patient’s body not being imaged receive minimal radiation exposure.

What are the limitations of barium enema?

A barium enema is usually not appropriate for someone who is in extreme abdominal pain or who has had a recent colonic biopsy. If perforation of the colon is suspected, the enema should be performed with a water-soluble contrast solution.

X-ray imaging is not usually indicated for pregnant women.