Expert testing and diagnosis

Specialist assessment together with comprehensive use of the most advanced diagnostic techniques and expert interpretation lead to correct diagnosis.

Why diagnostic tests for acid reflux are required

Sometimes it may seem obvious to a patient that their symptoms are caused by acid reflux. With other people, it may be mistaken for other problems and their symptoms may go unrecognised as acid reflux for years.

Therefore, a specialist may recommend special tests to confirm a diagnosis of acid reflux disease, exclude other diseases and help define the right treatment options.

Originally, tests were basic and uncomfortable but in recent years technology has progressed at a pace. It is now possible to identify, for instance, subtle problems with oesophageal function or non-acidic reflux with little discomfort.

Whilst these advanced testing methods tend to be accessible only through specialist centres we think they're invaluable in making the most accurate diagnosis.

Diagnosis is not always straightforward, so expert interpretation of the results is vital 

  • Endoscopy

    How is it performed?

    The endoscope is a long, thin flexible tube with a light and high resolution camera on its end. It is able to relay images of the inside of the body to a television screen. In the case of a gastroscope, the specialist will gently place an endoscope into the mouth, then through the oesophagus into the stomach and duodenum (the first part of the small intestine immediately beyond the stomach). The test usually only takes a few minutes and can be performed with local anaesthetic throat spray or under sedation.

    What will the test show?

    The operator will watch the image generated by the camera on a high definition screen. They will assess the lining of the oesophagus and stomach to look for possible abnormalities. These include Barrett’s oesophagus, evidence of inflammation caused by reflux (oesophagitis), ulcers and even cancer. They are likely to assess the size and type of a hiatus hernia, if present, which may determine suitability for surgery. If abnormalities are present then small samples of tissue called biopsies may be taken for analysis. Therapeutic procedures such as stretching of narrowing in the oesophagus can also be performed endoscopically.

  • Manometry

    What is it for?

    Manometry provides information about the function of the oesophagus. When we swallow, liquid and solids are normally propelled along the oesophagus into the stomach by co-ordinated contractions of muscle in its wall. This process is called peristalsis and requires co-ordination by complex nervous reflexes. In diseases of the oesophagus including GORD the normal function of the oesophagus can fail. We use a technique called high resolution manometry (HRM) which is the most up to date technology available. It assesses the co-ordination and strength of peristalsis, determines how well the upper (UOS) and lower oesophageal sphincters (LOS) are performing and how well solids and liquids travel through the oesophagus. It can identify disorders related to reflux as well as others that have alternative causes and may require different treatments.

    How is it performed?

    The test takes approximately 20-30 minutes. First, the nostril is numbed with a local anaesthetic spray. A small flexible tube called a catheter is passed through the nostril down into the oesophagus. The tube has tiny sensors which measure the pressure exerted by the muscles in the wall of the oesophagus. The patient will demonstrate swallowing food and drinking liquid, whilst the tube relays the information to a computer.

    What will the tests show?

    The information obtained from this test allows objective evaluation of the swallowing mechanism. For example, some patients with reflux-like symptoms may be found to be experiencing aerophagia (increased swallowing of air) or rumination (forced regurgitation of food). Recognising that these issues are occurring is important for optimised treatment, which is why expert interpretation of manometry findings is so important. Manometry is also essential to identify if a patient is suitable for anti-reflux surgery and if so what type of surgery will be best for you. For instance, your specialist will want to be sure that the strength of peristalsis in the oesophagus is sufficient to open the magnets in a LINX® device so swallowing will be easy following surgery. More information on the LINX® procedure can be found in the ‘Surgical Treatments’ section.

  • Catheter Reflux Testing

    What is it for?

    This is a test performed over a 24-hour period to determine how frequently fluid and/or gas from the stomach refluxes into the oesophagus. Traditionally, measuring reflux involves a pH test which measures acid exposure in the oesophagus over 24 hours. This can be very useful at determining abnormal acid reflux and its association with a patient’s symptoms. However, it has now become recognised that some patients’ symptoms are caused by reflux from the stomach which is not acidic. This can be missed by standard pH testing and consequently patients are told that their symptoms are not reflux-related when in fact they are. We therefore combine the pH test with impedance monitoring. Where the traditional method is limited to measuring only the presence or absence of acid, the combined test can also monitor episodes of non-acid reflux.

    How is it performed?

    A small tube called a catheter containing a specially constructed probe is passed through the nostril to the back of the oesophagus. The probe detects the changes in electrical resistance and also measures the pH levels around the oesophagus. These measurements are relayed via the catheter to a portable recorder which is worn for the duration of the test. When symptoms are experienced they can be recorded by the patient by pushing a button. After the 24-hour test is complete the probe is removed and the data collected for interpretation. Although the procedure can feel uncomfortable, it is not usually painful.

    What will the tests show?

    By measuring impedance combined with traditional pH measures, any movement of gas or liquid is recognised, regardless of acidity, allowing a more thorough evaluation. As well as reflux and reflux symptoms, swallowing behaviours such as aerophagia can be studied and their association with reflux recorded by the probe. Impedance-pH monitoring is also able to evaluate the extent of reflux along the length of the oesophagus or beyond the larynx (voice box). This is especially useful for evaluating reflux symptoms affecting the throat, including globus (a lump in the throat feeling), hoarseness and chronic cough. These symptoms are common, especially in laryngo-pharyngeal reflux (LPR), which can be related to reflux of all kinds.

  • Bravo® Catheter Free Reflux testing

    What is it for?

    Some patients may be unable to tolerate the small catheter used in impedance-pH testing. In other cases a catheter test may provide insufficient evidence of reflux, despite your specialist believing that this is the cause of your symptoms. This can occur because some patients find it difficult to behave normally with a catheter in position - for instance, they may find eating difficult. It may also be the case that the impedance-pH test records insufficient results due to the normal day to day variation in reflux. A Bravo® test may therefore be recommended.

    How is it performed?

    The test involves inserting a tiny capsule into the bottom of the oesophagus. This is done during an endoscopy which can be performed under sedation and takes just a few minutes. The capsule measures acid reflux in the oesophagus and relays the information to a small recorder in the same way as in a standard catheter test. The difference, however, is that this information is relayed wirelessly without a catheter and the patient is unaware of the physical presence of the monitoring capsule.

    What will the test show?

    In the same way as an impedance test, the Bravo® will record reflux in the oesophagus. The test usually takes place over a much longer period (at least 48 hours). It therefore often demonstrates reflux when a catheter test has been negative as there is a greater chance of reflux occurring during the time period. However, the disadvantage is that it will not demonstrate non-acidic reflux and does not record any information regarding oesophageal function, and so does not replace a manometry test. Currently the Bravo® is usually complementary to the other oesophageal tests and is used in conjunction with them.

  • Breath tests

    What is it for?

    Breath tests are most commonly used to diagnose small intestinal bacterial overgrowth (SIBO) and malabsorption of sugars such as lactose or fructose. Malabsorption is the imperfect absorption of food material by the small intestine. These conditions can cause similar symptoms to reflux and can occur independently or co-exist with GORD. Identifying their existence is important as if they go unrecognised patients may undergo unnecessary surgery, or, if surgery is performed, they may find that it works poorly or that they experience side effects. For instance, if a patient has bloating caused by SIBO, a Nissen’s fundoplication procedure may worsen this symptom.

    How is it performed?

    A sample of the patient’s breath is analysed. The exhaled breath is tested to measure the production of hydrogen and methane gases by gut bacteria.

    What will the test show?

    In the case of SIBO, fermentation of food by bacteria in the small bowel can inhibit normal absorption, produce gas, and increase the number of substances called short chain fatty acids in the gut. This can lead to symptoms of bloating, nausea and cramping as well as altered bowel habit. Performing a breath test allows diagnosis based on measurement of both hydrogen and methane. This means better characterisation of gut bacteria, which enables tailored treatment regimens based on accurate diagnosis.

  • Ear, Nose and Throat Tests

    Patients experiencing symptoms in the mouth or throat may be advised to undergo special investigations.
    These include;

    CT Scan

    CT scan is now a routine investigation. It uses X-rays and computer technology to create images of the body.

    MRI Scan

    Magnetic Resonance Imaging (MRI) is now a routine investigation. It is a non-invasive and painless test that uses magnetic and radio waves to create clear pictures showing the inside of your heart. Unlike an X-ray, an MRI scan does not use radiation.


    This can be performed in different ways: - Indirect laryngoscopy. This uses a small mirror held at the back of your throat. The examining specialist will shine a light on the mirror to view the throat area. -Fiberoptic laryngoscopy (nasolaryngoscopy). This test employs a small flexible telescope. This is passed through your nose and into your throat after a local anaesthetis spray is used to numb the throat. This is the most common way that the voice box is examined. This procedure typically takes less than 1 minute. - Direct laryngoscopy. This employs a tube called a laryngoscope. This procedure allows the doctor to see deeper in the throat and to remove a foreign object or sample tissue for a biopsy. It is performed under general anaesthetic.

    Sinus X-ray

    A sinus X-ray is an imaging test that uses X-rays to look at your sinuses. The sinuses are air-filled pockets (cavities) near your nasal passage.

  • Respiratory Tests

    Patients with respiratory symptoms such as a cough or asthma may undergo tests depending upon the type of symptoms they experience. These include;

    Chest X-Ray

    A simple x-ray to image the bones and soft tissues in the chest including the lungs and heart.


    Bronchoscopy is a procedure to look directly at the airways in the lungs using a small flexible camera called a bronchoscope.

    CT Scan of the Chest

    CT scan is now a routine investigation. It uses X-rays and computer technology to create images of the body.

    Lung Scan

    A lung scan is an imaging test to look at your lungs and help diagnose certain lung problems. A lung scan may also be used to see how well treatment is working.

    Peak Flow Measurement

    Peak flow measures air flowing in and out of the lungs. Pleura

    Pulmonary Function Tests

    Pulmonary function tests (PFTs) are non-invasive tests that assess the how well the lungs are functioning.

    Pulse Oximetry

    Pulse oximetry measures oxygen level (oxygen saturation) in the blood.