Anorectal Manometry

Anorectal manometry is a diagnostic test useful in determining what may be the cause of your child’s constipation, stool accidents, or other bowel concerns. This test studies how the muscles and nerves in the anus and rectum are working by measuring pressures.

What to Expect

This test will take approximately 30 minutes.  Your child will be asked to change into a gown and undress from the waist down.  They will be asked to lie on their left side. A soft, small and flexible tube will be placed into the rectum. A tiny deflated balloon is attached to the end of the tube. During the test, this balloon will be filled with small amounts of air to measure how your child's muscles and nerves work inside the rectum. The tube is attached to a computer that measures how well the rectal muscles work. The provider will slowly inflate or deflate the balloon, and the computer will record the activity of the muscle and nerves in response to the balloon.

The provider will ask your child to tell them when they feel the balloon as it inflates. The provider may also ask your child to squeeze down on the balloon or try to push the balloon out of the rectum. This should not be uncomfortable. The provider will remove the tube when the test is finished.

How to Prepare

We will provide instructions for a prep to make sure there is no stool in the rectum. The prep will be tailored to your child based on developmental age, ability to tolerate rectal therapy (enemas) and level of constipation. Preps may include enemas and/or MiraLAX®.

Your child should not have anything to eat or drink for 2 hours prior to the test.

The test should not cause pain. However, it is normal for your child to feel anxious about the test.  We recognize that this procedure can be frightening to children and their families.  We have child life specialists who are available to work with us, to help children and families navigate this procedure and make everyone feel as comfortable as possible.  

It is very helpful if you discuss this procedure ahead of time with your child. Encourage them to bring a comfort item like a stuffie, blanket or an iPad/phone for distraction.

A member of our GI team will contact you prior to the procedure to go over further instruction and scheduling.

Risks of the Test

Anorectal manometry is a very safe and low risk procedure.  It is unlikely to cause any pain.  Complications are rare, but include a perforation or tear in the rectum and bleeding from the rectum.

After the Test

Once the test is completed, your child will be discharged home on the same day.  Your provider will review the data from the test and a final report should be ready within 1-2 weeks of the procedure date.  The finalized report will be communicated with the child’s caregiver, the primary care provider, and other care providers as indicated.