Health Library

Contrast Enema

Contrast Enema


This is a test which uses X-rays and a special kind of enema solution and/or air to take pictures of the colon or large bowel, which is the lower part of the intestines. The test shows the doctor if there are abnormalities of the colon or distal small intestine.

Types of Positive Contrast Enemas

  • A contrast enema uses an enema fluid that shows up on X-ray. There are special preparations for this test. This test is commonly used for patients with chronic constipation to help diagnose a disorder called Hirschsprung's disease.
  • An air contrast barium enema uses air along with an enema fluid, barium, that shows up on X-ray. Air contrast barium enemas are frequently done to look for a source of rectal bleeding (such as a polyp). Bowel preparation is required for this test.

Before the Test

Before you come to the hospital, explain to your child what will happen. For young children, use simple words and explain shortly before the test.

Contrast Enema Preparation

Please follow the instructions that apply to the test for which your child is scheduled. The instructions differ depending on the type of contrast enema.

Air Contrast Barium Enema Preparation

Beginning the day before the test, your child may only have clear liquids all day. No solid food should be eaten. Clear liquids include water, broth, clear juices such as apple, cranberry, and fruit punch, Kool-Aid or soft drinks.

If your child is taking medicine ordered by a doctor, give it at the scheduled times. Milk, chewing gum, hard candy or mints should not be given to your child.

If the test ordered requires a bowel preparation (if you are not sure, call radiology at 513-636-6386), your child will need to drink two doses of an over-the-counter laxative such as magnesium citrate, which can be purchased at a pharmacy or drugstore.

If your child will be coming to Cincinnati Children's as an outpatient for this test, give the magnesium citrate at 3 pm (or after school) on the day before the test, and again at bedtime the night before the test. The chart below shows the amount to give.


 Child's Age  Dose to Give
 Under 1 year  No laxative
 1-2 years  1½ ounces
 3-5 years  2½ ounces
 6-8 years  3 ounces
 9-12 years  4 ounces
 13-18 years  5 ounces


On the day of the test, your child may have clear liquids up until four hours before the test. Do not allow your child to eat or drink anything for four hours before the test.

During the Test

Staying With Your Child

You are encouraged to stay with your child during the test. Children are often more cooperative and less apprehensive when a loved one is with them. It is easier to have another caregiver watch your child's siblings so you can be with your child. If you are pregnant, you will have to stand behind a glass window inside the fluoroscopy suite or leave the room when the pictures are being taken.

It is possible that during the procedure your child may experience some discomfort. Please encourage your child to tell the doctor, nurse or technologist if pain occurs so it can be evaluated.

Contrast Enema

During the test, your child will lie on the X-ray table. The enema involves the insertion of a small tube in your child's rectum. This tube, smaller than a normal bowel movement, may be uncomfortable but should not cause pain. The enema tube will remain in place during the exam. He / she will be given an enema. The liquid will outline your child's colon. The X-ray technologist or doctor (radiologist) will be looking with a special X-ray camera during this test. During the test, several X-ray pictures will be taken. The entire test itself lasts about 15 minutes. The X-ray technologist will keep you informed.

Nothing should hurt during the test, but your child will need to lie still on the X-ray table. If your child is unable to lie still, our staff will assist your child in holding still.

Air Contrast Barium Enema

Similar to the barium enema described above, your child will have a tube inserted into the rectum and be given an enema of special liquid called barium. However some of the barium will then be drained and air put in. The barium and air will outline your child's colon on the X-rays. The X-ray technologist or doctor (radiologist) will then take several X-ray pictures. The exam itself may take about 30-45 minutes. The X-ray technologist will keep you informed.

Again, nothing should hurt your child during the test, but the air will cause your child to feel rather distended, but he / she will need to lie still on the X-ray table. If your child is unable to lie still, our staff will assist your child in holding still.

After the Test

The technologist will tell let you know when all the X-ray pictures are taken. Your child may return to normal daily activities. Results of the test will be sent to your child's doctor's office within 24 hours. Your doctor will contact you with the results.

After the contrast enema test, it is helpful for your child to drink plenty of liquids to help him / her to pass the enema out of the colon. Give your child liquids like juices, water, Kool-Aid or fruit punch.

Immediately after the exam, you child may have a liquid stool if a barium enema was given. It is possible that your child's stool may appear to be whitish in color for 24 to 48 hours after the test due to the enema that was given. Whitish stools are not cause for concern. Encouraging your child to drink fluids will allow his / her stool to return to normal within a short time.

If your child experiences a significant amount of pain or shows any new symptoms out of the ordinary for your child, call your primary doctor.

Last Updated 01/2020

Reviewed by Becci Pryor, BS, CRA, RT(R)