Manometry and pH Studies.
Oesophageal manometry measures how well the muscles of the food pipe are working. A 24-hour pH study monitors acid levels in the oesophagus over a full day and night. The two tests are often performed together and are commonly required before anti-reflux surgery.
When these tests may be recommended.
- Difficulty swallowing (dysphagia)
- Pain on swallowing (odynophagia)
- Heartburn or reflux not well controlled by medication
- Chest pain without a cardiac cause
- Pre-operative assessment for anti-reflux surgery or hiatus hernia repair
- Suspected achalasia or oesophageal motility disorder
- Assessment of medication effectiveness for reflux
What each test measures and how it works.
Oesophageal manometry
Oesophageal manometry, also known as oesophageal physiology studies, measures the pressure and coordination of muscle activity along the food pipe. A thin, flexible tube containing pressure sensors is passed through the nose, along the back of the throat and down into the stomach. You will be asked to swallow small sips of water while the sensors record how the muscles of the oesophagus contract and relax. The test measures peristalsis (the wave-like motion that moves food toward the stomach) and the function of the lower oesophageal sphincter (the valve connecting the oesophagus to the stomach). Problems with either can cause difficulty swallowing, heartburn or chest pain.
24-hour pH study
A 24-hour pH study monitors the levels and changes in acid in the oesophagus over a full day and night while you go about your normal activities. A small tube is passed through the nose into the oesophagus in the same way as for manometry. This tube is connected to a small recording device worn on a belt for 24 hours. You will be asked to keep a food and symptom diary during this period, recording meals, activity and any symptoms you experience. The test is used to confirm whether acid reflux is occurring, how frequently, whether episodes correlate with your symptoms, and how well any medication you take is working.
Before, during and after your tests.
Booking and preparation
A valid referral from your GP or specialist is required. Once your referral is received, our reception team will contact you. You will receive detailed written instructions before your test. You will typically be asked to fast for at least 4 to 6 hours before the procedure and may be asked to stop certain medications, including proton pump inhibitors, in advance.
The manometry test
A thin flexible tube is passed through your nose and guided into the stomach. A local anaesthetic spray is used to numb the nose and throat, which makes the process more comfortable. The tube is positioned and you will swallow small sips of water while the pressure sensors record muscle function. The test takes approximately 30 to 45 minutes.
The 24-hour pH study
If a pH study is also being performed, a smaller tube is passed through the nose in the same way as for manometry. This is connected to a small recording device you will wear on a belt for the following 24 hours. You will be asked to keep a diary of all food, drink and symptoms over that period. The tube and device are returned to the clinic the next day.
Results and follow-up
Results are reviewed by your surgeon and discussed at your next appointment. The findings directly inform surgical planning, particularly for anti-reflux surgery, where manometry and pH data are used to select the most appropriate procedure for your anatomy and symptoms.
How to arrange manometry and pH studies.
To book oesophageal manometry or a 24-hour pH study, please ensure you have a valid referral from your GP or specialist. Once your referral has been received, our reception team will contact you to complete your booking and provide preparation instructions.
If you have any questions before your test, please call our team.