24-hour pH/Impedance Probe Study

A pH/impedance probe study checks if your child has reflux. Reflux happens when fluid in the stomach moves into the esophagus (the tube that carries food from the mouth to the stomach). It also helps us determine the amount of acid in the fluid by measuring the pH of the fluid and its movement.

The study uses a thin, soft tube (probe) placed in your child’s esophagus. It measures how many times fluid comes up (quantity) and how often it happens (frequency). This helps your doctor decide the best treatment for your child.

Your child’s doctor wants to know: 

• If your child has fluid that causes aspiration, and the acid level of the fluid
• How frequently the fluid moves from the stomach to the back of the throat
• The best way to treat it

The pH/impedance probe is a thin tube about the size of a cooked spaghetti noodle that is soft and bends easily. It goes through your child’s nose and into the esophagus. An X-ray will help make sure the impedance probe is in the right place.

The probe connects to a small monitor that records fluid movement and acid levels for 24 hours. Information from the study gives doctors detailed information about your child’s reflux that cannot be learned from a physical examination or other kinds of tests.

Placing the probe takes only about 10 minutes, but your child will stay in the hospital overnight so the monitor can record for a full day.

On the day of the study:

• Food and liquids: Follow your doctor’s instructions for when your child should stop eating and drinking.
• Medicines: Follow your doctor’s instructions about whether your child should take their usual medicines, including reflux medicine.
• Pack a bag. Bring:
  • Comfortable clothes for overnight
  • A favorite book or toy
  • A comfort item (like a stuffed animal) for probe placement

• Stay calm. Your child will feel more relaxed if you are calm.
• Talk and hold their hand during probe placement.
• The probe does not hurt, but it may feel strange or uncomfortable for a short time.
• If you are pregnant or think you might be, please bring another adult to stay with your child during the X-ray.

• A nurse will secure the probe in place, but if it comes out, the study may need to be repeated. You may need to help keep your child from pulling on the probe.
• We will have you press a button to record when you are seeing specific symptoms like coughing or choking.
• Take notes. We will give you a form to write down:
  • When your child eats or drinks
  • Any symptoms you notice (like coughing or discomfort)
• Follow eating instructions. Your child can only eat and drink at certain times during the study

• The probe will be removed, and you’ll get instructions for going home.
• Your child may have a sore throat or feel tired for a day.
• Your doctor will call you in a few days with the results.
• Your child can return to their regular diet and medications after the study.

Call the Nurse Help Line at 651-229-3890 if you have any questions or concerns before your appointment.