Specialist Upper Gastrointestinal & Bariatric Surgeon

Secretary: Nicola Symons

Telephone: 01872 226150

Specialist Upper Gastrointestinal & Bariatric Surgeon

Oesophageal Physiology & Endoscopy

As a specialist in gastro-oesophageal disease, Mr Clarke offers the most up-to-date investigation techniques including endoscopy, high resolution manometry, 24-hour pH & impedance testing.


What are oesophageal physiology studies?

Oesophageal physiology studies are a series of investigations that are used to accurately assess the muscle function in your gullet (oesophagus) and stomach, as well as measure levels of acid reflux over at least a 24 hour period. They involve two key investigations, a high resolution manometry test and 24-hr pH / impedance test.

Why might my specialist recommend these tests?

This test is often recommended in patients who are being considered for anti-reflux surgery, in order to assess how well the muscles of the gullet are functioning and whether there is a link between acid reflux and a patient’s symptoms. It is also valuable in the investigation of patients with difficulty swallowing (dysphagia), to exclude disorders affecting the muscles of the oesophagus (gullet) such as achalasia or distal oesophageal spasm.

What do the tests involves?
High Resolution Manometry (HRM)
  • A thin tube is gently passed into a nostril to the back of your nose. You will then be asked to drink a cup of water through a straw, which will help to move the tube down through your oesophagus into the stomach. Your breathing will not be affected during the procedure.
  • Once the tube has been passed you may have the sensation of a ‘lump’ in the back of your throat. It will feel slightly uncomfortable rather than painful and will settle quickly.
  • You will then be asked to lie down.
  • The tube in your oesophagus will be connected to the equipment which measures how well the muscles in your oesophagus are working. This recording takes approximately 10 minutes. During this time you will be asked to be still, quiet and have relaxed breathing. You will also be asked to swallow small mouthfuls of water at regular intervals until the test is complete.
24-hour pH (acid) / impedance monitoring
  • A thin tube is gently passed into a nostril to the back of your nose. You will then be asked to drink a cup of water through a straw, which will help to move the tube down through the oesophagus into the stomach. Your breathing will not be affected during the procedure.
  • Once the tube has been passed there will be the sensation of a ‘lump’ in the back of your throat. It will feel a little uncomfortable rather than painful and will settle within quickly.
  • The end of the tube will be positioned in your oesophagus above your stomach.
  • The tube will be taped to the outside of your nose, passed around your ear and attached to a small recording box which is worn on a shoulder strap or belt around your waist for 24 hours.
  • You will be given instructions before you leave and asked to fill in a special diary of your meals, bedtimes and symptoms.
  • You will be sent home and be able to eat, sleep and carry on normal daily routines.
  • You will be asked to return the following day to have the tube removed. This takes a few seconds and is painless.
Are there any risks or side effects?
  • Both tests are usually very safe. They might cause some discomfort but should not be painful.
  • You may feel slightly sick when the tube is first positioned, but this should settle quickly.
  • Other mild side effects may include: sore throat, nosebleed, a runny nose, fainting or wheezing.
  • There is a very small risk that the probe could damage the oesophagus, but this is highly unlikely as the tube is very flexible and the practitioner who does the test has specialised training.
  • During the test most patients are able to carry on as normal. Some prefer not to work because they feel self-conscious about having a tube coming out of their nose.

NB If you have any allergies please inform the practitioner carrying out your test. If you are pregnant, please inform the department by telephone before your appointment.

What happens afterwards?
  • You may go back to normal activities.
  • You can eat and drink normally.
  • When you return after 24 hours to have the tube removed you may restart any medication you were asked to stop.
  • Your test results will be analysed personally by Mr Clarke, who will issue a report and be able to discuss the results with you at your next clinic appointment.


What is an upper GI endoscopy?

This is a procedure in which a thin flexible telescope is passed via the mouth to examine the lining of the oesophagus (gullet), stomach and small intestine (duodenum). It has a tiny light and a camera at one end that enable the images to be displayed on a television screen.

Why might I need an upper GI endoscopy?

This may be recommended to investigate symptoms such as:-

  • Difficulty swallowing (dysphagia)
  • Persistent upper abdominal pain
  • Acid reflux
  • Persistent nausea and vomiting
  • Vomiting blood
  • Unexplained weight loss
How do I prepare for the test?

You must not eat or drink for at least 4 hours before the procedure, although you may drink a small cup of water up to 2 hours before the test. You should take your regular prescription medications, unless you are otherwise advised by Mr Clarke to stop any specifically for the test.

Should I have throat spray or sedation?

The test is normally carried out whilst you are conscious, using either throat spray (local anaesthetic to numb the back of your throat) or a sedative injection to make you slightly drowsy. Most people tolerate it with throat spray alone, allowing quicker recovery after the procedure and return to normal. If you do have a sedative there is a longer recovery, you cannot drive, work or operate machinery for 24 hours and you would need someone to take you home and stay with you for that period too.

What happens during the test?

You will be positioned comfortably on your left side and a small mouthguard placed to protect your teeth. Once the throat spray or sedation has been given, the small telescope will be passed through your mouth and into your throat. It will not interfere with breathing. Air is passed through the telescope to give a better view, which can make you feel bloated or the need to belch. Any saliva that collects in your mouth is removed by the nurse using a sucker.

During the test a tissue sample (biopsy) may be taken for laboratory examination. This is normally painless. Sometimes a treatment such as stretching of a narrow area (dilatation) may also be performed.

What happens after the test?

The test normally takes between 5-20 minutes. If you have throat spray you cannot eat or drink for one hour after the procedure, as the local anaesthetic temporarily affects your swallowing. If you have sedation, a friend or relative should collect you and ideally stay with you for 24 hours, during which time you should not drive, work or operate machinery.

Are there any risks?

Complications are very uncommon following diagnostic endoscopy (less than 1 in 1000) but may include bleeding, perforation or a reaction to the sedative drug. If you develop difficulty swallowing, increasing abdominal or chest pain, pass black or bloody stools, have a fever or are worried, you should contact your GP or emergency department.

How do I get the results?

Mr Clarke will discuss the results with you immediately after the test and will provide a written report for you to take home. A copy will also be sent to your own GP.


Very down to earth, made me feel very comfortable and reassured

May 2024

Extremely proficient, professional and considerate surgeon

April 2024

I felt confident and safe from the first appointment. I would recommend Michael Clarke especially to anyone worried about forthcoming op

March 2024

Very professional and easy going manner. Excellent understanding of my understanding and ability to suggest courses of action

February 2024

Very professional, personable and I felt listened to

February 2024

Mr Clarke was most reassuring, provided clear guidance and options. Altogether inspired confidence throughout

December 2023

Mr Clarke gave me confidence in his knowledge from our first meeting. he also listened to my questions

September 2023

Explained things well in a way people understand, good bedside manner

September 2023

Mr Clarke not only put me at ease at the first consultation but such is his manner and explanation that I felt confident throughout. If surgery can be a good experience, this was.

4th October 2022

I felt completely at ease, a friendly approach and a sense of humour. Would definitely recommend.

1st July 2022

Excellent Consultant who made me feel totally at ease and confident that he would return me to full health - which he did.

29th April 2022

Very pleasant surgeon to talk to and very reassuring. Explained everything in clear language.

20th October 2021

Mr Clarke was courteous and respectful to me and explained my condition and treatment required. I was very happy with my post op recovery and had very little pain. I would not hesitate to contact Mr Clarke if I ever needed his help again.

29th May 2021

Mr Clarke made me feel completely at ease and confident in his ability through his mannerisms and professionalism. Mr Clarke was exceptional on the day. I'd be happy for him perform surgery on me again.

15th April 2021

I felt that Mr Clarke listened to me really well and thoroughly investigated my symptoms before deciding surgery was the best option

22nd March 2021

The whole experience from start to finish was done in a very empathetic and professional way. I was given ample time for questions and all tension and worry was removed form the procedure.

9th March 2021

I highly commend his approachable friendly manner. He made me feel at ease and informed through all aspects of my treatment and surgery.

15th January 2020

Surgery, care and follow-up were carried out to a very high standard. I wouldn't hesitate to recommend Mr Clarke to others.

18th December 2019

I found Mr Clarke extremely confident in this line of surgery, knowledgeable and very nice. Had a great ability to keep me at ease throughout.

8th June 2019

Perfect from referral to discharge. Everything explained fully. Every discussion with Mr Clarke was perfectly judged.

1st December 2018

Mr Clarke was outstanding from the start of my treatment to the end. He was empathetic, knowledgeable, respectful and made you feel at ease.

23rd August 2018

Mr Clarke was extremely efficient both in consultation and surgery. He was very caring and took time to explain procedures. I would highly recommend him.

24th January 2018

Very pleased with outcome of op from Mr Clarke. Just like 2016 he was very helpful and so professional. Would definitely recommend.

27th January 2018

Excellent manner both in consultation, pre- and post-op. Would definitely be happy to see him and recommend to others requiring surgery.

13th October 2017

Mr Clarke made the whole experience a breeze. So calm, polite and understanding of patients' needs.

13th September 2017

My introduction to Mr Clarke was met with a warm smile and a firm handshake. He was professional and friendly and put me at ease. I have no hesitation in recommending Mr Clarke.

9th August 2017

Mr Clarke did everything he said he would. Appointments came through quickly and I was made to feel comfortable and I had confidence in Mr Clarke from the outset.

1st June 2017

Mr Clarke has been most helpful to my specific situation. He made allowances for me and adapted to my particular health issues.

24th February 2017

Mr Clarke could not have done more for me. He looked after me and made me feel important and safe.

23rd February 2017

Whole experience was very professional, so felt safe in his hands. Communication so important and Mr Clarke was brilliant.

1st December 2016

Due to unforeseen circumstances, the contact details for my secretary have changed. Please use the new contact details for Nicola Symons listed in the top right hand corner of my main webpage.

If you have been in touch using the old contact details in the last 14 days and not yet received a reply, please contact me using the new contact details.