What is it?

The objective of a 24-hour pH study in children is to measure the acidity in the oesophagus over a period of 24 hours. This is done with the aid of a pH probe. This test is mainly performed when reflux is suspected or when there are recurrent respiratory infections.

What is the process?


On arrival at the hospital, register your child with the Admission Department. You are expected at the Children’s Department at 9am.

It is important that your child is fasting. This means that your child is not allowed to eat or drink from 6.30am and is not to allowed to do so again until after the probe has been placed. Your child needs to have fasted to avoid that he or she will vomit when the probe is placed.

Placing of the probe

A probe is inserted through the nose to just above the stomach entry. To prevent your child from accidentally removing the probe, both arms will be splinted. That way, your child will not be able to bend their arms and therefore, not be able to touch their nose. For babies younger than three months, we put socks over their hands.

During the test

If you are staying with your child overnight, we will ask you to record a few things. This will help the paediatrician to interpret the test. If you do not stay overnight, then the nurse will do this.


The physician will discuss the result with you the morning after the test.


See the leaflet below for more information.

Centres and specialist areas


Latest publication date: 05/08/2021
Supervising author: Dr Degraeuwe Jelle