In most cases, your GP will be able to diagnose gastro-oesophageal reflux disease (GORD) by asking you some questions about your symptoms.

Further testing for GORD is usually only required if:

• you are having difficulty swallowing (dysphagia)
• your symptoms do not improve despite taking medication

Further testing aims to confirm or disprove the diagnosis of GORD while checking for any other possible causes of your symptoms, such as cancer of the oesophagus.

Endoscopy

An endoscopy is a procedure where the inside of your body is directly examined using a piece of medical equipment that is known as an endoscope.

An endoscope is a long, thin flexible tube that has a light source and a video camera at one end so that images of the inside of your body can be sent to an external monitor.

To confirm a diagnosis of GORD, the endoscope will be inserted into your mouth and down your throat. The procedure is usually done while you are awake, and you may be given a sedative to help you to relax.

An endoscopy is used to check whether the surface of your oesophagus has been damaged by stomach acid. It can also rule out more serious conditions that can also cause heartburn, such as stomach cancer.

Manometry

If an endoscopy does not find any evidence of damage to your oesophagus, you may be referred for a further test called manometry.

Manometry is used to assess how well your lower oesophageal sphincter (LOS) is working by measuring pressure levels inside the sphincter muscle.

During manometry, one of your nostrils will be numbed using a topical anaesthetic. A small tube will then be passed down your nostril and into your oesophagus to the site of the LOS. The tube contains a number of pressure sensors, which can detect the pressure that is generated by the muscle, then send the reading to a computer.

During the test, you will be asked to swallow some food and liquid to check how effectively your LOS is functioning.

A manometry test takes around 20 to 30 minutes to complete. It is not painful, but you may have some minor side effects including:

• a nosebleed
• a sore throat

However, these side effects should pass quickly once the test has been completed.

Manometry can be useful for confirming a diagnosis of GORD, or for detecting less common conditions that can disrupt the normal workings of the LOS, such as muscle spasms or achalasia (a rare swallowing disorder).

24-hour pH monitoring

If the manometry test cannot find any problems with your oesophageal sphincter muscles, another test known as 24-hour pH monitoring can be used (pH is a unit of measurement that is used in chemistry, and describes how acidic a solution is). The lower the pH level, the more acidic the solution is.

The 24-hour pH monitoring test is designed to measure the pH levels around your oesophagus. You should stop taking any medication that is used to treat GORD for seven days before having a 24-hour pH test because the medication could distort the test results.

During the test, a small tube containing a probe will be passed through your nose to the back of your oesophagus. This is not painful but it can feel a little uncomfortable.

The probe is connected to a portable recording device that is about the size of a MP3 player, which you wear around your wrist. Throughout the 24-hour test period, you will be asked to press a button on the recorder every time you become aware of your symptoms.

You will be asked to complete a diary sheet by recording when you have symptoms upon eating. Eat as you normally would to ensure that an accurate assessment can be made.

After the 24-hour period is over, the probe will be removed so that measurements on the recorder can be analysed. If the test results indicate a sudden raise in your pH levels after eating, a confident diagnosis of GORD can usually be made.