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GI Physiology Services

GI physiology services at St John & St Elizabeth Hospital are designed to diagnose and treat conditions related to the gastrointestinal (GI) tract, particularly the stomach and oesophagus. These specialised services help identify the root causes of symptoms such as difficulty swallowing, heartburn, regurgitation, and chest pain. Our expert team utilises advanced diagnostic tests to provide accurate assessments and tailored treatment plans.

Also known as: gastrointestinal physiology services

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Everything You Need to Know

GI physiology services encompass a range of diagnostic tests aimed at evaluating the function of your stomach and oesophagus. These tests are particularly useful for identifying issues that may not be apparent through standard examinations. If you experience persistent GI symptoms or would like to consider more drastic intervention to manage your symptoms such surgical procedures, these tests can provide valuable insights into the underlying causes, enabling more effective treatment and tailored operations.


Types of GI Physiology Tests and Services


Catheter-based Tests

High Resolution Oesophageal Manometry:

Assesses the muscle contractions and valve function in the oesophagus.

  • Evaluation of oesophageal motility disorders
  • Diagnosis of achalasia, oesophageal spasm, and other motility disorders
  • Assessment of lower oesophageal sphincter (LOS) function

Ambulatory pH and Impedance Monitoring:

Measures the acidity levels and reflux activity of any time including non-acid and bile within the oesophagus over a 24-hour period.

  • Detection and monitoring of gastroesophageal reflux disease (GORD)
  • Evaluation of non-acidic and weakly acidic reflux
  • Identification of reflux-symptom association (if reflux proven, does it explain symptoms)


No-Catheter Tests

Hydrogen-Methane breath tests (home testing):

  • Diagnosis of small intestinal bacterial overgrowth (SIBO)
  • Diagnosis of intestinal methanogenic overgrowth (IMO)
  • Assessment of carbohydrate malabsorption (e.g., lactose and fructose intolerance)
  • Identification of H. Pylori gastric infection

Oesophageal biofeedback therapy:

Customised therapy for motility disorders, reflux, and dysphagia special cases where focus is retraining brain-gut axis

Catheter-Based Tests

Before the Test

Preparing for your GI physiology test is crucial to ensure accurate results and a smooth experience. Here are the steps to follow before your test:


Your initial consultation with one of our specialists will involve a thorough review of your medical history, symptoms, and any previous treatments. This helps determine the most appropriate tests for your condition.

If you have already had your consultation with your GP or specialists, you will not need to repeat this step here.

Pre-Test Instructions

To prepare for your test, you will receive detailed instructions, which may include:

  • Medication Adjustments: Some medications can affect the test results. You may be instructed to stop taking certain medications several days before the test. For example:
    • 7 Days Before: Stop taking proton pump inhibitors such as Omeprazole, Lansoprazole, Pantoprazole, Esomeprazole, and Rabeprazole.
    • 2 Days Before: Stop taking H2 blockers like Ranitidine, Cimetidine, Nizatidine, and Famotidine.
    • 24 Hours Before: Stop taking antacids such as Gaviscon, Rennies, and Peptac.
  • Fasting: Do not eat or drink anything for at least 6 hours before the test. This ensures that your stomach is empty and provides more accurate results.
  • Special Conditions: If you are diabetic, you will be advised to stop taking your diabetic medications for the duration of fasting therefore it will be helpful to get advise from your healthcare professional on any concerns you may have. If you suffer from any other condition that my affect your testing process please contact us in advance using the contact details in this page.

Day of the Test

On the day of the test, wear loose, comfortable clothing. It is generally not necessary to bring a companion unless you have a specific condition that requires assistance. However, friends or family who accompany you will need to wait in the designated area during the test.

Upon arrival, you will be asked to read and sign a consent form after ensuring you fully understand the procedure and its risks. The physiologist will be available to answer any last-minute questions you might have.

During the Test

Our state-of-the-art facilities and experienced team ensure your comfort and safety throughout the GI physiology tests.

High Resolution Oesophageal Manometry

This test assesses the muscle contractions and valve function in your oesophagus. Here’s what to expect:

  • Preparation: You will be asked to take a seat, and the physiologist will explain the procedure in detail.
  • Procedure: A numbing agent (Xylocaine) will be used in your throat and nostril. A manometry catheter, a thin tube with pressure sensors, will be gently inserted through your nose and down into your oesophagus. You will be asked to drink small sips of water to help the tube pass into your stomach. Once in place, the catheter will be taped to your nose, and you may feel a slight lump sensation in your throat.
  • Assessment: The catheter measures the pressure exerted by the oesophageal muscles as you swallow. The physiologist will ask you to swallow small amounts of water and possibly eat specific foods like pieces of bread to evaluate how well your oesophagus functions.
  • Duration: The test usually takes about 15-20 minutes

Ambulatory pH and Impedance Monitoring

This test measures the acidity and reflux activity in your oesophagus over a 24-hour period. It is typically performed immediately after the manometry test when needed.

  • Preparation: After completing the manometry test, the physiologist will insert a second, thinner catheter in a similar manner.
  • Procedure: The catheter has sensors to measure pH levels and impedance. It will be secured to your cheek and connected to a small, portable recorder worn around your waist or shoulder.
  • Monitoring Period: You will be instructed on how to operate the recorder and fill out a diary, noting when you experience symptoms, eat, drink, and go to bed. It is important to maintain your normal activities during this period to ensure accurate results.
  • Restrictions: You will not be able to shower or bathe while the equipment is in place, but you can eat and drink normally.

Post-Test Instructions

After 24 hours, you will remove the tube yourself and return the device in a prepaid envelope for analysis. You will then be able to resume any medications that were stopped before the test and return to your normal routine.

After the Test

Our commitment to your care continues well beyond the testing process. Here’s what to expect after your GI physiology tests:

Immediate Post-Test Care

After the catheters are removed, you may experience minor throat irritation or discomfort, which should resolve quickly. You can resume your normal activities, including eating and drinking, and restart any medications that were paused for the test.

Follow-Up Care

The data collected from your tests will be thoroughly analysed by our specialists. The results will be sent to the consultant who referred you for the tests. You will then have a follow-up appointment to discuss the findings and next steps in your treatment plan.

  • Results Discussion: During your follow-up appointment, your consultant will explain the test results in detail, addressing any questions or concerns you may have. This is an opportunity to understand how your symptoms are related to the function of your stomach and oesophagus.
  • Treatment Plan: Based on the test results, your consultant will work with you to develop a personalised treatment plan. This may include medication, dietary changes, lifestyle modifications, surgical options or further diagnostic procedures.

Long-Term Management

Effective management of your GI symptoms involves ongoing care and monitoring. Your treatment plan may involve regular check-ups to ensure that your condition is being managed effectively.

  • Lifestyle and Dietary Adjustments: Your consultant may recommend specific changes to your diet and lifestyle to help alleviate symptoms. This could include avoiding certain foods, eating smaller meals, and adopting a healthier lifestyle.
  • Medication Management: If medications are part of your treatment plan, follow your consultant’s instructions carefully. Regular follow-ups will help to adjust dosages and address any side effects.
  • Further Testing: In some cases, additional tests may be needed to monitor your condition or assess the effectiveness of your treatment.

How to pay for your treatment

If you’re… paying for yourself

Did you know you don’t need private medical insurance to come to St John & St Elizabeth Hospital? As a self-pay patient, you can access safe, outstanding quality health care at times to suit you.

For scans and tests, as well as to see most consultants, you’ll still need to be referred by a medical professional like your GP, but as a self-pay patient, the process is more straightforward. You won’t need authorisation from an insurance provider, and you’ll have greater choice of consultant and appointment times.

If you’re… paying for yourself

Did you know you don’t need private medical insurance to come to St John & St Elizabeth Hospital? As a self-pay patient, you can access safe, outstanding quality health care at times to suit you.

For scans and tests, as well as to see most consultants, you’ll still need to be referred by a medical professional like your GP, but as a self-pay patient, the process is more straightforward. You won’t need authorisation from an insurance provider, and you’ll have greater choice of consultant and appointment times.

Appointment and Treatment Plan


Initial Consultation

Your journey begins with a detailed consultation with a GI specialist. During this appointment, your medical history, symptoms, and any previous treatments will be reviewed. This initial discussion helps to determine the most appropriate diagnostic tests and treatment options for your condition.


Personalised Treatment Plan

Based on your initial consultation, a tailored treatment plan will be developed. This plan outlines the specific tests you will undergo and the subsequent steps based on your results. The treatment plan is designed to address your unique needs and optimise your recovery and well-being.


Diagnostic Tests

The diagnostic tests, such as high resolution oesophageal manometry and ambulatory pH and impedance monitoring, will be performed by our skilled physiologists. These tests are essential for accurately diagnosing the cause of your symptoms and formulating an effective treatment plan.


Follow-Up and Treatment Implementation

Following the tests, you will have a follow-up appointment to discuss the results and finalise your treatment plan. This may include:

  • Medications: Prescribed to manage symptoms and improve GI function.
  • Lifestyle and Dietary Changes: Recommendations to help alleviate symptoms and improve overall health.
  • Further Diagnostic Procedures: If necessary, to gather additional information or monitor your condition.

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