Patient guide · Reviewed 2026-07-30
Gastro-oesophageal reflux monitoring, pH-impedance, Bravo wireless and MII testing — beyond the PPI trial.
Reflux monitoring measures acid and non-acid reflux over 24 to 96 hours. It uses either a thin catheter (pH-impedance) or a wireless capsule clipped to the oesophagus (Bravo). It confirms GORD, sorts out reflux that PPIs have not helped, and picks the right patients for anti-reflux surgery.
Key facts
- 01
Definition
24 to 96 hours of acid and non-acid reflux monitoring — the objective measure of how much reflux is really happening.
- 02
Catheter pH-impedance (MII)
Trans-nasal catheter records both acid and non-acid reflux episodes over 24 hours.
- 03
Bravo wireless capsule
Capsule clipped to the oesophageal wall records for 48–96 hours — no nasal tube.
- 04
DeMeester + Lyon criteria
Composite DeMeester score and Lyon Consensus thresholds define pathological reflux.
- 05
Symptom–reflux correlation
SAP and SI link individual symptoms to recorded reflux episodes.
- 06
Confirms PPI-refractory reflux
Selects patients for anti-reflux surgery when medication is failing.
Preparation
From consultation to report — what happens, in order.
Reflux monitoring is a short day-case study — the outcome depends on stopping PPIs correctly and keeping an honest symptom diary.
- 01
Before
Consultant gastroenterology consultation
Clinical review confirms reflux monitoring is the right test and which system suits you.
- 02
Before
Stop PPI seven days pre-test
Proton-pump inhibitors are withheld for a week to expose true acid exposure — an alginate may bridge symptoms.
- 03
On the day
Attend day-case unit
Short outpatient visit — no general anaesthetic, no overnight stay.
- 04
On the day
Choose catheter or wireless system
MII pH catheter for acid plus non-acid detail; Bravo wireless capsule if a nasal tube isn’t tolerable.
- 05
On the day
Recording 24–96 hours
Catheter records for 24 hours; Bravo capsule for 48–96 hours in normal daily activity.
- 06
After
Symptom diary maintained
You log meals, position and symptom episodes — the diary drives SAP and SI calculations.
- 07
After
Written report with all reflux metrics
Acid exposure time, DeMeester score, episode counts and symptom correlation, with a clear next step.
What it shows
The metrics that come off a reflux study.
Reflux monitoring gives objective numbers — acid exposure time, DeMeester, symptom correlation — that direct treatment rather than continued empirical PPI.
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Total acid exposure time
Percentage of the recording with oesophageal pH below 4 — the primary Lyon Consensus metric.
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Non-acid reflux episodes
Weakly acidic and non-acid liquid or gas reflux detected by impedance channels.
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Symptom association (SAP / SI)
Statistical link between logged symptoms and recorded reflux events.
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DeMeester composite score
Six-parameter composite quantifying pathological acid reflux over 24 hours.
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Nocturnal reflux burden
Supine reflux — associated with laryngopharyngeal and pulmonary complications.
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PPI-responsive vs PPI-refractory
Separates true reflux failing therapy from functional heartburn and hypersensitive oesophagus.
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Functional heartburn (Rome IV)
Normal acid exposure with negative symptom correlation — a distinct neurogastro diagnosis.
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Red flag: severe reflux plus Barrett’s on gastroscopy — surveillance pathway
Long-segment or dysplastic Barrett’s triggers formal endoscopic surveillance, not more monitoring.
Next steps
What the study directs you towards.
The result shapes therapy — from PPI optimisation and alginates to LINX, fundoplication or neurogastro pathways for functional heartburn.
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PPI optimisation
Dose, timing and split-dose regimens tailored to the recorded acid exposure profile.
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Alginate or H2-blocker adjunct
Gaviscon-type alginate raft or nocturnal H2 blocker for breakthrough or post-prandial reflux.
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Lifestyle intervention
Weight, meal timing, elevation, alcohol and trigger foods — evidence-based and often under-used.
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Anti-reflux surgery (LINX / fundoplication)
Magnetic sphincter augmentation or Nissen / Toupet fundoplication for confirmed pathological reflux.
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TIF endoscopic anti-reflux
Transoral incisionless fundoplication — a scarless option for selected anatomy.
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Neurogastro therapy for functional heartburn
Low-dose neuromodulators and psychological therapy where the oesophagus is hypersensitive, not refluxing.
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Repeat monitoring post-surgery
On-therapy pH-impedance to confirm control after fundoplication or LINX.
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MDT review
Gastroenterology, upper-GI surgery and dietetics discuss borderline or complex cases together.
Red flags
When reflux monitoring isn’t the first step.
Some presentations need endoscopy, imaging or an urgent cancer pathway before — or instead of — a reflux study.
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Barrett’s oesophagus with dysplasia
Requires formal endoscopic surveillance and consideration of endoscopic eradication therapy.
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Grade C or D oesophagitis
Severe erosive disease — diagnosis is made at endoscopy and treatment is escalated immediately.
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Refractory reflux post-fundoplication
On-therapy monitoring plus manometry to characterise wrap failure or slippage.
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Extra-oesophageal reflux (LPR / asthma)
Cough, laryngitis or hoarseness needing ENT and respiratory input alongside pH monitoring.
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Scleroderma oesophagus
Absent peristalsis and hypotensive LOS — profound reflux exposure and management challenges.
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Post-bariatric reflux
De novo or worsening reflux after sleeve gastrectomy — bariatric MDT involvement required.
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Persistent dysphagia
Priority endoscopy to exclude stricture, eosinophilic oesophagitis or malignancy first.
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Alarm features (weight loss, bleeding, anaemia)
Two-week-wait pathway — imaging and endoscopy take precedence over reflux monitoring.
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Suspected malignancy on endoscopy
Any suspicious lesion mandates biopsy, staging and upper-GI cancer MDT referral.
Sources
The guidelines behind this page.
Reviewed against current British and international gastroenterology consensus. Next review 2027-07-30.
- British Society of Gastroenterology — guidelines on oesophageal manometry and reflux monitoring.
- Lyon Consensus 2.0 — modern diagnosis of gastro-oesophageal reflux disease.
- American College of Gastroenterology — clinical guideline for the diagnosis and management of GERD.
- European Society of Neurogastroenterology and Motility — reflux testing standards.
Frequently asked
Everything we get asked about reflux monitoring.
Catheter vs Bravo, stopping PPIs, the DeMeester score, and when anti-reflux surgery becomes appropriate.
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What is gastro-oesophageal reflux monitoring?
A 24–96 hour recording of acid and non-acid reflux in the oesophagus, either via a thin trans-nasal catheter (pH-impedance / MII) or a wireless capsule clipped to the oesophageal wall (Bravo). It objectively quantifies reflux burden and correlates episodes with your symptoms.
-
What is the difference between a catheter and a Bravo capsule?
The catheter is a 24-hour recording via a fine tube through the nose — it captures both acid and non-acid reflux (impedance). The Bravo capsule is a wireless system placed at endoscopy that records pH for 48–96 hours with nothing in the nose, but does not measure non-acid reflux.
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Do I need to stop my PPI before the test?
For a diagnostic study to confirm or exclude reflux disease, PPIs are usually stopped for seven days. For post-surgical or refractory reflux workup, testing may be performed on therapy — your gastroenterologist will decide.
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What are the DeMeester score and the Lyon Consensus?
The DeMeester score is a composite of six pH parameters; the Lyon Consensus defines pathological acid exposure time (>6% of the recording) as the primary diagnostic threshold, with adjunctive metrics including reflux episode number and symptom association.
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What is SAP and SI?
Symptom Association Probability and Symptom Index — statistical measures linking symptoms in your diary to recorded reflux events. A positive SAP or SI supports reflux as the cause; negative values suggest functional heartburn.
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When is anti-reflux surgery appropriate?
Objectively confirmed pathological reflux that is refractory to optimised medical therapy, or where the patient prefers a definitive option, may qualify for LINX magnetic sphincter augmentation or fundoplication — always after pH-impedance and oesophageal manometry.
Related tests
Looking for a different test?
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Bravo pH study
Wireless 48–96 hour pH capsule — no nasal tube.
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Bravo Alpha oesophageal pH
Extended-duration wireless oesophageal pH monitoring.
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Oesophageal manometry
High-resolution motility study — mandatory before anti-reflux surgery.
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All tests
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In practice, in London
Booking gastro oesophageal reflux monitoring privately in London — what actually happens
With gastro oesophageal reflux monitoring, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. The NHS route for gastro oesophageal reflux monitoring is thorough, but the queue is real. Most patients we speak with have been told to expect anywhere from a handful of weeks to several months, depending on their local trust and how the referral is graded. Going private in London usually collapses that window to a matter of days — often the same week if the diary allows. It isn’t about jumping a queue so much as buying time back while you still have the flexibility to plan around it.
The mechanics are straightforward: a consultant appointment, any tests done at a nearby CQC-registered site, and a written report back within a few days. London’s density of private diagnostics — Marylebone, the City, Chelsea, Canary Wharf — means most patients can find something that fits around work without a cross-town trek. For gastro oesophageal reflux monitoring specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
Honesty about expectations is part of the job. A private gastro oesophageal reflux monitoring appointment in London won’t change the underlying medicine — the guidelines, the consultants, and the equipment are largely the same as on the NHS. What it changes is speed, continuity, and the amount of time you get to actually talk through the findings. Everyone we route to is GMC-registered and works within CQC-regulated facilities.
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