Barium Enema

Approved by the Cancer.Net Editorial Board, 07/2021

A barium enema is a type of x-ray that allows your doctor to see your colon and rectum. It is also called a colon x-ray or lower GI exam. Barium enemas can help diagnose changes to your large intestine, such as your colon and rectum.

Your doctor might recommend a barium enema to find inflammation, polyps, or cancer in your colon or rectum. The most common reason you may need a barium enema is after rectal surgery. Your doctor will confirm that your body has healed before reversing an ileostomy.

About the colon and rectum

Your colon and rectum are a major part of your digestive system, also called the gastrointestinal tract. These organs help your body process the food it does not use, which becomes waste (feces). The colon is the biggest part of your large intestine. It empties into the rectum, where waste collects as bowel movements. The rectum empties into the anus, where bowel movements leave the body.

The drawing below shows the different parts of the colon and rectum.

How does a barium enema work?

Barium is a contrast medium, which helps radiologists and radiology technicians see details on an x-ray. Barium is not radioactive. It is a white, chalky substance that is mixed with water.

During a barium enema, a radiologist or radiology technician injects the barium liquid into your rectum during an enema. They then take x-rays of your large intestine with the substance inside your body. The barium helps show the shape and features of your large intestine.

Who gives a barium enema?

A radiology technician or a radiologist performs a barium enema. It is done in an x-ray room in either a hospital or a doctor's office. After the procedure, the radiologist reads the results and diagnoses or confirms any abnormalities.

How should I get ready for a barium enema?

When you schedule the barium enema, you will get detailed instructions on how to prepare, such as what to eat and how to empty your colon. Below, you will find general information about how to get ready for a barium enema. The specific instructions you receive may be different. Always follow the instructions of your health care team before your barium enema.

What to eat. Your colon must be complete empty for the barium enema. Only eat soft foods or clear liquids for 1 to 3 days beforehand. This includes fat-free bouillon or broth, black coffee, and strained fruit juice. You will not be allowed to eat or drink anything after midnight on the day of your procedure.

Empty your colon. You will need to take a laxative or give yourself a regular enema the day or night before your appointment. This removes any remaining waste from your colon. If your doctor prescribes a laxative, it will be either a pill or a powder that you mix with water before drinking. The laxative will make you use the bathroom frequently. Make sure you have easy access to the toilet during this time.

What to wear. Right before your barium enema, you will be asked to remove all clothing, jewelry, and other metal objects that can interfere with the x-ray. You will be given a hospital gown to wear.

Your medications and health history. Ask if you should take your usual medications on the day of the test. This includes prescription drugs, over the counter drugs, and supplements that you take. Let the health care staff know if you have any medical conditions or if you could be pregnant. X-rays can be harmful to a developing baby.

Allergies. Let the health care staff know about any drug allergies or other allergies that you have.

Insurance, cost, and consent. If you are concerned about the cost of your test, contact your insurance company beforehand. Ask how much of the cost you will have to pay.

When you arrive for your test, you will be asked to sign a consent form. This form says you understand the benefits and risks of the procedure and agree to have it. Be sure to ask the health care team about any questions or concerns you have.

What happens during a barium enema?

During the barium enema, the doctor or technician will ask you to lie on your side on an exam table in a private room. They will drape a sheet over your body.

The exam table is attached to an x-ray machine and a video monitor. The x-ray technician will first take several x-rays to make sure your colon is empty.

The doctor or technician will then insert a well-lubricated enema tip attached to a tube into your anus. The barium will flow through the tube into your colon.

During the test, the doctor or technician may ask you to move into different positions. This is so the barium can flow through the entire colon.

Once the radiologist determines there is enough barium in the colon, they may deliver a small amount of air into the colon through the same tube. This step is called a "double contrast barium enema." It inflates the bowel and produces a better view of the intestinal wall. Several x-rays will be taken during this time. When an x-ray is taken, the barium shows up bright white, clearly outlining the colon and rectum.

A barium enema usually takes 20 to 30 minutes.

Is a barium enema painful?

A barium enema can be uncomfortable for several reasons. You may feel mild stomach pressure and cramping when the barium flows through the colon. Taking slow, deep breaths can help you relax.

You may also feel discomfort from lying still for a long time. Once the barium is inserted into the colon, you may also feel the urge to have a bowel movement. It is important for you to try to hold in the barium until the test is complete.

What happens after a barium enema?

Once the radiologist has taken enough images of the colon, they will remove the enema tip. You will be helped down from the table so you can go to the restroom to push out the barium. You will then return to the exam room for another x-ray to make sure you have emptied your bowel enough.

You can go back to your usual activities immediately after the barium enema. But you should have someone else drive you home from the test.

You may notice gray or white stool for several days after a barium enema. That is the remaining barium leaving your body.

Drink plenty of fluids for the next several days to prevent constipation and help remove the remaining barium. Your health care team may also recommend taking a laxative.

Call your doctor’s office immediately if you have:

  • Severe stomach pain

  • Fever

  • Bloody bowel movements

  • Dizziness

  • Weakness

Questions to ask your health care team

Before your barium enema, consider asking the following questions:

  • Why are you recommending this procedure for me?

  • Who will perform the barium enema? Who else will be in the room?

  • What will happen during the test?

  • How long will it take?

  • Will it be painful?

  • Are there risks associated with having a barium enema?

  • Will I need to avoid any activities afterward?

  • How accurate is a barium enema at finding cancer?

  • When and how will I learn the results?

  • Who will explain the results to me?

  • What other tests will I need if the barium enema finds evidence of cancer?

Related Resources

Guide to Colorectal Cancer


More Information X-ray (Radiography) - Lower GI Tract

MedlinePlus: Barium enema