Acid and non-acid reflux in patients with persistent symptoms despite acid suppressive therapy: a multicentre study using combined ambulatory impedance-pH monitoring

High-resolution manometry and impedance-pH/manometry: valuable tools in clinical and investigational esophagology

Both high-resolution manometry (HRM) and impedance-pH/manometry monitoring have established themselves as research tools and both are now emerging in the clinical arena. Solid-state HRM capable of simultaneously monitoring the entire pressure profile from the pharynx to the stomach along with pressure topography plotting represents an evolution in esophageal manometry. Two strengths of HRM with pressure topography plots compared with conventional manometric recordings are (1) accurately delineating and tracking the movement of functionally defined contractile elements of the esophagus and its sphincters, and (2) easily distinguishing between luminal pressurization attributable to spastic contractions and that resultant from a trapped bolus in a dysfunctional esophagus. Making these distinctions objectifies the identification of achalasia, distal esophageal spasm, functional obstruction, and subtypes thereof. Ambulatory intraluminal impedance pH monitoring has opened our eyes to the trafficking of much more than acid reflux through the esophageal lumen. It is clear that acid reflux as identified by a conventional pH electrode represents only a subset of reflux events with many more reflux episodes being composed of less acidic and gaseous mixtures. This has prompted many investigations into the genesis of refractory reflux symptoms. However, with both technologies, the challenge has been to make sense of the vastly expanded datasets. At the very least, HRM is a major technological tweak on conventional manometry, and impedance pH monitoring yields information above and beyond that gained from conventional pH monitoring studies. Ultimately, however, both technologies will be strengthened as outcome studies evaluating their utilization become available.

Acid reflux detection and symptom-reflux association using 4-day wireless pH recording combining 48-hour periods off and on PPI therapy

OBJECTIVES

Studies have shown that extended pH recording improves the sensitivity of esophageal pH monitoring. Controversy exists as to whether pH studies are optimally done off or on proton pump inhibitor (PPI) therapy. The aim of this study was to incorporate periods both off and on PPI therapy in a single, extended pH test and describe the effect of PPI therapy on symptom-reflux associations.

METHODS

Sixty patients underwent 4-day pH recordings using two separate receivers calibrated to a single wireless pH capsule. Patients were off PPI therapy for days 1 and 2. Either rabeprazole 20 mg twice daily or omeprazole/sodium bicarbonate 40 mg twice daily were administered on days 3 and 4. Symptom-reflux correlation was determined by the symptom index (SI), symptom sensitivity index (SSI), and symptom association probability (SAP).

RESULTS

Twenty studies were excluded due to premature detachment (9) or incomplete data capture for >6 of the 96-h period (11). Off therapy, 14 patients (35%) had abnormal esophageal acid exposure values. On day 4, 39 patients (98%) had normal acid exposure. The number of symptoms and acid reflux events were significantly higher off PPI therapy. Furthermore, the percentage of patients with a positive SI fell from 50% off PPI to 9% on PPI (P < 0.01), whereas 63% of patients symptomatic off PPI therapy became asymptomatic on PPI therapy and could not have an SI calculated. Similarly, the SAP was abnormal in 45% of patients off PPI therapy but only 10% on PPI therapy (P < 0.01).

CONCLUSIONS

Extended pH recording improves the detection of abnormal acid reflux and increases the number of recorded symptoms and acid reflux events. Combined off and on PPI therapy pH testing enhances the interpretation of pH monitoring and symptom-reflux correlations, which can be helpful in the management of patients with PPI-unresponsive gastroesophageal acid reflux symptoms.

Non-acidic supraesophageal reflux associated with diffuse alveolar damage and allograft dysfunction after lung transplantation: a case report

Advances in lung transplantation have improved 1-year survival rates, but allograft dysfunction continues to be a significant cause of post-transplant death. Diffuse alveolar damage is an early indication of allograft dysfunction and has been linked to gastroesophageal reflux. We report a case of diffuse alveolar damage-associated allograft dysfunction in a patient found to have significant non-acid gastroesophageal reflux.

Mechanisms of heartburn

Heartburn is a typical symptom of GERD. The spectrum of diseases associated with GERD includes reflux esophagitis, Barrett's esophagus and nonerosive reflux disease (NERD). Although acid reflux is the classic cause of heartburn in patients with erosive esophagitis, the relationship between acid and heartburn is far from clear, especially in patients with NERD. Strong evidence exists that weakly acidic reflux and/or non-acid-related events have a significant role in the generation of heartburn. In addition to the role of nonacidic refluxate components, activation of mechanoreceptors and chemoreceptors, and a possible role for central and peripheral sensitization, has been described. Although patients with erosive esophagitis respond well to acid-suppressive therapy, the same does not hold true for those with NERD. NERD represents a major clinical problem, and its management remains a challenge. Discussion of NERD focuses on the mechanisms that cause chest pain in this subgroup of patients. Improved understanding of the pathogenesis underlying heartburn in patients with GERD, in particular those with NERD, will shape our understanding of this condition. Such understanding will serve as a platform for further research and allow additional therapies to be developed for this increasingly encountered clinical condition.

Reflux monitoring: current status

Gastroesophageal reflux monitoring is a key investigation in managing gastroesophageal reflux disease. Esophageal pH monitoring is used to quantify esophageal acid exposure and the association of symptoms with acidic reflux episodes. Recently available wireless pH monitoring systems allow reflux monitoring over prolonged periods and increase patient comfort during the procedure. Combined impedance-pH monitoring offers the ability to identify reflux episodes independently of their acid content, an important advantage when evaluating patients with symptoms persisting during acid-suppressive therapy.

Acid and non-acid reflux patterns in patients with erosive esophagitis and non-erosive reflux disease (NERD): a study using intraluminal impedance monitoring

BACKGROUND

Non-erosive reflux disease (NERD) and erosive esophagitis (EE) are the most common phenotypic presentations of gastroesophageal reflux disease (GERD).

AIM

To assess acid and non-acid reflux patterns in patients with EE and NERD using combined esophageal pH-impedance monitoring.

METHODS

A total of 26 GERD patients off acid-suppressive medication and ten healthy volunteers (HV) underwent upper endoscopy and 24-h pH-impedance monitoring. Analysis of the pH-impedance signals included total reflux time, number of reflux episodes according to gas-liquid composition, and pH (acid, non-acid).

RESULTS

EE was identified in 13 patients and NERD in 13 patients. Pathologic acid reflux was found in 92.3 and 69.2% of patients with EE and NERD, respectively (P = 0.15). When compared to HV, EE patients and NERD patients showed a higher incidence of acid (P = 0.002 and P < 0.001, EE vs. HV and NERD vs. HV, respectively) and non-acid reflux episodes (P = 0.03 and P = 0.001, EE vs. HV and NERD vs. HV, respectively). Mean reflux times, as assessed by both pH-metry and impedance monitoring, and incidence of acid and non-acid reflux episodes were similar in EE and NERD patients. In the supine position, however, EE patients showed a higher incidence of acid (P = 0.048) and liquid reflux episodes (P = 0.07).

CONCLUSION

Whereas EE patients have more acid reflux episodes in the supine position than NERD patients, patients with EE and NERD have similar non-acid reflux patterns. This observation lends support to the notion that non-acid reflux is less damaging to the esophageal mucosa than acid reflux.

New esophageal function testing (impedance, Bravo pH monitoring, and high-resolution manometry): clinical relevance

Esophageal testing aims to quantify gastroesophageal reflux or characterize esophageal motility. Reflux monitoring traditionally has been based on the detection of acidic reflux by a transnasal catheter that measures esophageal pH. Recently there have been two major developments in this field: the wireless Bravo pH capsule (Medtronic, Inc., Minneapolis, MN), which allows catheter-free monitoring, and impedance-pH measurement, a catheter-based technique that enables detection of acidic and nonacidic reflux. The assessment of esophageal motility has relied on conventional manometry for many years. Two new procedures also recently became available to assess esophageal motility: high-resolution manometry, which uses many closely spaced pressure sensors and provides spatiotemporal plots of esophageal pressure changes, and impedance manometry, a test that directly measures bolus transit and provides conventional manometric data. The advantages, disadvantages, and clinical importance of these new esophageal tests are discussed in this review.

Total fundoplication controls acid and nonacid reflux: evaluation by pre- and postoperative 24-h pH-multichannel intraluminal impedance

BACKGROUND

Studies have demonstrated that Nissen fundoplication controls acid gastroesophageal reflux (GER). Combined 24-h pH and multichannel intraluminal impedance (MII-pH) allows detection of both acid and nonacid GER. Antireflux surgery is considered for any patient whose medical therapy is not efficient, particularly patients with nonacid gastroesophageal reflux disease (GERD). Nevertheless, fundoplication used to control nonacid reflux has not been reported to date.

METHODS

In this study, 15 consecutive patients who underwent laparoscopic Nissen-Rossetti fundoplication had MII-pH both before and after the surgical procedure. The numbers of acid and nonacid GER episodes were calculated with the patient in both upright and recumbent positions.

RESULTS

The 24-h pH monitoring confirmed the postoperative reduction of exposure to acid (p < 0.05). Postoperatively, the total, acid, and nonacid numbers of GER episodes were reduced (p < 0.05).

CONCLUSION

According to the findings, MII-pH is feasible and well tolerated. It provides an objective means for evaluating the effectiveness of Nissen-Rossetti fundoplication in controlling both acid and nonacid GER.

Effect of proton-pump inhibitor treatment on symptoms and quality of life in GERD patients depends on the symptom-reflux association

BACKGROUND

Gastroesophageal reflux disease patients demonstrate various pathophysiologic backgrounds. Therefore, a heterogeneous response to proton-pump inhibitor (PPI) treatment can be expected. We investigated the effect of short-term PPI treatment on symptoms and quality of life (QOL) in primary care patients with and without pathologic esophageal acid exposure and in presence or absence of a positive association between symptoms and reflux episodes.

STUDY

Seventy-four heartburn patients were categorized into 4 groups according to positive or negative symptom-reflux association, as expressed in symptom index, symptom sensitivity index, and symptom association probability (SAP) and presence or absence of pathologic reflux, defined as esophageal pH<4%>6% of the time (pH+/pH-). Overall and specific reflux symptoms were assessed 1 week before and the last week during a 2-week course of 40-mg esomeprazole daily. The QOL was scored by the Quality of Life in Reflux and Dyspepsia questionnaire 2 weeks before treatment and directly after.

RESULTS

Using the SAP to assess symptom-reflux associations, the 4 groups [SAP+pH+(n=40); SAP+pH-(n=12); SAP-pH+(n=10); SAP-pH-(n=10)] had similar demographic characteristics. The SAP-pH- subgroup had the least overall symptom reduction (P<0.01) and in the SAP+pH+ subgroup the greatest heartburn symptom reduction was found (P<0.02). The residual symptom scores on treatment were lowest in SAP+pH+ and highest in SAP-pH- subgroups and relatively high in the SAP+pH-. QOL was severely reduced and SAP-pH- patients had the lowest QOL overall. Similar findings were made using symptom index and symptom sensitivity index.

CONCLUSIONS

Symptomatic reflux patients without evidence of reflux disease on a 24-hour pH recording responded less favorably to PPI treatment than patients with a positive symptom-reflux association or with pathologic reflux.

Impedance-pH monitoring: new standard for measuring gastro-oesophageal reflux

Impedance monitoring is a new technique that can be used to detect the flow of fluids and gas through hollow viscera. With impedance monitoring gastro-oesophageal reflux can be detected independent of its acidity by differences in electrical impedance between the mucosal surface, fluids and gas that surround the catheter. Clinically, it is used in combination with oesophageal pH monitoring, and the combination of impedance-pH monitoring allows recognition of both acidic and weakly acidic reflux episodes. Studies have shown that impedance-pH monitoring is useful in the evaluation of patients with proton pump inhibitor-resistant typical reflux symptoms, as it provides a higher yield in detecting reflux as the cause of a patient's symptoms compared to pH monitoring alone. It is therefore likely that impedance-pH monitoring will largely replace pH monitoring in the next 5 years and it will become the standard for reflux detection.

Characteristics of symptomatic reflux episodes on Acid suppressive therapy

BACKGROUND

Persistent symptoms on acid suppressive therapy are due to either acid or nonacid gastroesophageal reflux (GER) episodes or are not related to reflux.

AIM

To compare physical and chemical characteristics of GER episodes associated with symptoms in patients on acid suppressive therapy.

METHODS

Patients with persistent symptoms on acid suppressive therapy underwent combined impedance-pH monitoring. Reflux episodes were classified as acid if nadir pH was <4.0, and nonacid if it remained at >/=4.0, separated into liquid-only or mixed (liquid-gas), and considered to reach the proximal esophagus if liquid was present 15 cm above the lower esophageal sphincter (LES). Reflux episodes were considered symptomatic if patients recorded a symptom within 5 min after the reflux episode. Risk factors of symptomatic reflux episodes were identified using multivariable generalized estimating equations (GEEs).

RESULTS

One hundred twenty patients (85 women, median age 54 yr, range 18-85 yr) recorded 3,547 reflux episodes (84.3% nonacid, 50.6% mixed), of which 468 (13.2%) were symptomatic. Based on multivariable GEE analysis with episode-level symptom status (symptomatic vs nonsymptomatic) as the outcome variable, reflux episode acidity was not significantly associated with symptoms (P= 0.40). Mixed reflux episodes were significantly associated with symptoms relative to liquid-only episodes (odds ratio [OR] 1.49, 95% confidence interval [CI] 1.19-1.87, P= 0.0005), as were reflux episodes reaching the proximal esophagus compared with those reaching the distal esophagus only (OR 1.28, 95% CI 1.06-1.55, P= 0.012).

CONCLUSION

The majority of reflux episodes on acid suppressive therapy are asymptomatic. Reflux episodes extending proximally and having a mixed (liquid-gas) composition are significantly associated with symptoms, irrespective of whether pH is acid (<4) or nonacid (>/=4).

An analysis of persistent symptoms in acid-suppressed patients undergoing impedance-pH monitoring

BACKGROUND & AIMS

Despite proton-pump inhibitors (PPIs), patients may have persistent symptoms of gastroesophageal reflux disease (GERD). We aimed to identify symptom types and frequency experienced by patients on PPI therapy, and to identify the type of reflux, if any, associated with these symptoms.

METHODS

A retrospective review was performed of 200 patients on PPI with GERD symptoms during ambulatory impedance-pH testing. The symptom index (SI) was determined for each symptom, and an SI of 50% or more was considered positive. Patients were divided into 2 groups: those with exclusively nonacid reflux (NAR) episodes and those with mixed-acid and NAR episodes. Symptom profiles were compared between these 2 groups.

RESULTS

A total of 415 symptoms were reported by the 200 patients on twice-daily PPIs. Throat clearing was most common (24%). A total of 110 (27%) were typical symptoms and 305 (73%) were atypical. Typical symptoms were more likely to have a positive SI than atypical symptoms (48% vs 25%, P < .01). Eighty-four patients (42%) had a positive SI, and 116 patients (58%) had a negative SI. One hundred patients (50%) had only NAR; the other 100 had mixed acid and NAR. Heartburn (21% vs 63%, P < .01) and nausea (8% vs 44%, P < .01) were more likely associated with reflux in the mixed-acid and NAR group.

CONCLUSIONS

Patients on PPIs still experience GERD symptoms. Impedance-pH monitoring identifies similar symptom associations with all types of reflux and also clarifies symptoms not related to any reflux.

Pathogenesis of gastro-oesophageal reflux disease and novel options for its therapy

Better understanding of the mechanisms that lead to reflux disease is an important area for future research, given the very high prevalence of this problem. During the lifetime of this journal, much has been learnt about the pathophysiology of reflux disease. Abnormally, frequent acid reflux plays a key role in pathogenesis: this reflux occurs predominantly during transient lower oesophageal sphincter relaxations. Analysis of the literature suggests that the importance of transient relaxations as the major permissive event for occurrence of acid reflux is currently substantially underestimated. 'Transient relaxation' is an inexact descriptor, as this motor programme includes inhibition of the diaphragmatic hiatus and distal oesophageal body circular muscle and contraction of the oesophageal longitudinal muscle. Laxity of the diaphragmatic hiatus and hiatus hernia are probably important factors that increase the probability for acid reflux to occur during transient relaxations and in allowing strain-induced reflux episodes. The importance of straining and low basal tone of the lower oesophageal sphincter in causing abnormal reflux has probably been overestimated, but these need more investigation. High resolution manometry is the key method for acquisition of important new insights into the normal and disordered mechanics of the antireflux function of the gastro-oesophageal junction, but as yet, the potential of this technique has been tapped relatively little. In the future, improved understanding of the mechanics of the gastro-oesophageal junction should lead to improved physical antireflux procedures. Much progress has been made in defining the control of transient relaxations and this has been translated into several promising options for a new class of drug that treats reflux disease by inhibition of transient relaxations. Clinical trials on these agents appear imminent.

Common causes and current guidelines

Chronic cough is a common and disabling symptom. Recent guidelines have attempted to provide direction in the clinical management of cough in both primary and secondary care. They have also provided a critical review of the available literature and identified gaps in current knowledge. Despite this they have been criticized for a reliance on a low quality evidence base. In this review, we summarize the current consensus on the clinical management of chronic cough and attempt to rationalize this based on recent evidence. We have also provided an overview of the likely pathophysiological mechanisms responsible for cough and highlighted areas, where knowledge deficits exist and suggest directions for future research. Such progress will be critical in the search for new and effective treatments for cough.

Heartburn refractory to proton-pump inhibitors

The most appropriate diagnostic and therapeutic approach to patients with heartburn that persists despite the use of proton-pump inhibitor (PPI) therapy currently is not known. In general, patients with heartburn refractory to PPIs may have more than one explanation for their persistent symptoms. These include uncontrolled esophageal acid exposure ("PPI failure") in a small subset of patients, as well as other potential etiologies in the majority of patients who have controlled esophageal acid exposure on PPI therapy ("PPI success"). Some potential explanations for persistent heartburn in this latter group include hypersensitivity to acid reflux, nonacidic or duodenogastric esophageal reflux, as well as functional heartburn. Patients who present with heartburn refractory to PPIs should be investigated further to determine the potential cause. We believe the diagnostic modality with the most clinical usefulness is 24-hour pH and multichannel intraluminal impedance monitoring with symptom index performed while the patient is on high-dose PPI therapy. This approach allows the patient to be properly categorized and also identifies a substantial proportion of patients who will have functional heartburn, a condition that should discourage the use of endoscopic or surgical therapies. Therapeutic options for patients with heartburn refractory to PPIs are limited and have not been thoroughly studied. As a result of the paucity of information, we favor a therapeutic approach based on the outcome of diagnostic testing.

The influence of co-morbid IBS and psychological distress on outcomes and quality of life following PPI therapy in patients with gastro-oesophageal reflux disease

BACKGROUND

A subset of patients with gastro-oesophageal reflux disease (GERD) does not achieve complete symptom resolution with proton pump inhibitor (PPI) therapy. The factors which affect response to PPI therapy in GERD patients remain unclear.

AIMS

To determine the prevalence and impact of irritable bowel syndrome (IBS) and psychological distress (PD) on GERD symptoms and disease-specific quality of life (QoL) before and after PPI therapy and to assess the same outcomes before and after PPI therapy in non-erosive reflux disease (NERD) and erosive oesophagitis (EO) GERD patients.

METHODS

Patients undergoing oesophago-gastroduodenoscopy (OGD) for heartburn were recruited. Participants completed validated surveys: Digestive Health Symptom Index, Reflux Disease Questionnaire, Quality of Life in Reflux and Dyspepsia and Brief Symptom Inventory (BSI). IBS was defined as >3 Manning criteria and PD as BSI score >63. At OGD, patients were classified as NERD or EO. Patients were treated with rabeprazole 20 mg/day for 8 weeks before completing follow-up surveys.

RESULTS

Of 132 GERD patients enrolled, 101 completed the study. The prevalence rates of IBS and PD were 36% and 41%, respectively. IBS independently predicted worse QoL before and after PPI therapy. PD independently predicted worse GERD symptoms and QoL before and after PPI therapy. There were no differences in symptoms or QoL between NERD and EO patients before or after PPI therapy.

CONCLUSIONS

IBS and PD impacted GERD symptoms and QoL before and after PPI therapy. Symptoms and QoL before and after PPI therapy were similar in NERD and EO patients.

Review article: respiratory manifestations of gastro-oesophageal reflux disease

BACKGROUND

Respiratory manifestations represent one of the most prevalent and difficult-to-manage extra-oesophageal syndromes of gastro-oesophageal reflux disease.

AIMS

To review the epidemiology, pathophysiological mechanisms and therapeutic outcomes of reflux-related respiratory disorders.

METHODS

Search of the literature published in English using PubMed database.

RESULTS

There is a discrepancy between the high prevalence of reflux in asthmatics and the limited efficacy of antireflux therapies. Asthma per se may cause reflux. Patients with difficult-to-treat asthma and/or nocturnal symptoms should be screened for reflux. Reflux can induce chronic cough through different mechanisms including micro-aspiration and both local and central reflexes. Cough and reflux may precipitate each other. A meta-analysis found no significant difference between placebo and proton pump inhibitors in the resolution of cough. Encouraging results have been reported, following antireflux surgery in patients selected on the basis of pH-impedance monitoring. Attention has been drawn to obstructive sleep apnoea syndrome.

CONCLUSIONS

The role of gastro-oesophageal reflux disease in the pathogenesis of miscellaneous respiratory disorders has been discussed for decades and established in asthma and cough. However, no major therapeutic advances have been reported recently. Future trials should concentrate on patient selection and the control of efficacy using recently developed technologies, such as pH-impedance monitoring.

Use of pH-impedance testing to evaluate patients with suspected extraesophageal manifestations of gastroesophageal reflux disease

GOALS

To report the use of pH-impedance testing in evaluating patients with suspected gastroesophageal reflux disease (GERD) with atypical symptoms.

BACKGROUND

Although the role of acid reflux in causing atypical GERD symptoms is generally accepted, the role, if any, of nonacid reflux is controversial, largely because until recently it has not been possible to detect nonacid reflux. The advent of intraluminal combined pH impedance testing (MII-pH), to detect nonacid reflux has heightened interest in its possible contribution to atypical symptoms.

STUDY

Fifty consecutive patients referred for MII-pH testing to evaluate the cause of atypical symptoms presumed due to GERD were evaluated. The symptoms were either refractory to acid inhibition therapy or so atypical that further work up was desired by the referring physician. Patients underwent MII-pH testing to determine whether reflux was present, and, if so, if it was due to acid, nonacid, or gas.

RESULTS

Only 16%, 22%, and 2% patients were found to have symptoms due to acid reflux, nonacid reflux, or both, respectively. Ten percent of these patients had gas reflux. MII-pH testing was useful in redirecting the management of patients who did not have reflux as the cause of their symptoms.

CONCLUSIONS

MII-pH testing is useful in determining whether gastroesophageal reflux is present in patients with atypical symptoms that have not responded to proton pump inhibitor therapy. It also distinguishes between reflux due to acid, nonacid, and gas, with consequences for management.

Refractory gastrooesophageal reflux disease

The introduction of proton pump inhibitors (PPIs) has facilitated the treatment of gastrooesophageal reflux disease (GORD) enormously; however, treatment of GORD still fails in a small proportion of patients. This small proportion of therapy-resistant patients encompasses a substantial part of the working load of physicians and has become a common clinical problem. A strong variability in acid-suppressive effect of PPI treatment exists depending on compliance, Helicobacter pylori status and genotype. Nocturnal acid breakthrough does not seem to be a major determinant of refractory GORD. Recent data, however, show that PPI-refractory GORD can result from nonacid reflux episodes. It is wise to reconsider the diagnosis of GORD in patients who are PPI-refractory. Most patients in whom a PPI is not effective do not have GORD, instead they suffer from other disorders such as functional dyspepsia. If after a thorough history is taken the suspicion of GORD is still high, the next step would be to perform upper endoscopy and reflux monitoring. In case patients truly have PPI-refractory GORD, therapy can be aimed at oesophageal hypersensitivity or a surgical solution can be sought.

Esophageal impedance-pH monitoring

Classical techniques like endoscopy and esophageal pH-metry are routinely used to study patients with symptoms related to gastroesophageal reflux disease (GERD). Although these techniques have been useful over the years both for diagnosis and therapeutic guidance, there are still many patients with typical or atypical GERD symptoms with normal endoscopy and pH-metry that do not respond adequately to antisecretory therapy. Ambulatory esophageal impedance-pH monitoring is a new technique that can be used to evaluate all types of gastroesophageal reflux, achieving higher rates of sensitivity and specificity than standard techniques. This review describes esophageal impedance-pH monitoring, summarizing the current literature on validation studies and clinical application.

Receptor-mediated uptake of pepsin by laryngeal epithelial cells

OBJECTIVES

Previous data suggest a mechanistic link between exposure to pepsin and cellular changes that lead to laryngopharyngeal disorders. Initial confocal microscopy analysis of pepsin uptake by cultured hypopharyngeal epithelial cells revealed that pepsin may be taken up by a specific process. The objective of this study was to use electron microscopy to confirm the initial confocal findings and to determine whether uptake of pepsin by laryngeal epithelial cells is receptor-mediated.

METHODS

Cultured human hypopharyngeal FaDu cells and human laryngeal biopsy specimens, taken from the posterior larynx of "control" patients without symptoms or findings of laryngopharyngeal reflux, were exposed to purified human pepsin 3b with or without transferrin (a marker for receptor-mediated endocytosis) in vitro. Uptake of pepsin was documented by electron microscopy.

RESULTS

Pepsin co-localized with transferrin in intracellular vesicles; this finding confirms that pepsin is taken up by laryngeal epithelial cells by receptor-mediated endocytosis.

CONCLUSIONS

This is a novel finding that further defines the role and mechanism of pepsin-mediated injury in laryngopharyngeal reflux. The objective of ongoing research is to identify the receptor and investigate potential antagonists as a new therapeutic option for patients with reflux-attributed disease--in particular, those patients who have persistent symptoms despite acid suppression therapy.

New algorithm for the treatment of gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease (GERD) is associated with a variety of typical and atypical symptoms. Patients often present in the first instance to a pharmacist or primary care physician and are subsequently referred to secondary care if initial management fails. Guidelines usually do not provide a clear guidance for all healthcare professionals with whom the patient may consult.

AIM

To update a 2002-treatment algorithm for GERD, making it more applicable to pharmacists as well as doctors.

METHODS

A panel of international experts met to discuss the principles and practice of treating GERD.

RESULTS

The updated algorithm for the management of GERD can be followed by pharmacists, for over-the-counter medications, primary care physicians, or secondary care gastroenterologists. The algorithm emphasizes the importance of life style changes to help control the triggers for heartburn and adjuvant therapies for rapid and adequate symptom relief. Proton pump inhibitors will remain a prominent treatment for GERD; however, the use of antacids and alginate-antacids (either alone or in combination with acid suppressants) is likely to increase.

CONCLUSION

The newly developed algorithm takes into account latest clinical practice experience, offering healthcare professionals clear and effective treatment options for the management of GERD.

How to manage refractory GERD

Patients who are unresponsive to 4-8 weeks' treatment with PPIs twice daily might have so-called refractory GERD. The first investigation these patients should undergo is upper endoscopy to exclude a diagnosis of peptic ulcer disease or cancer and identify the presence of esophagitis. The presence of esophagitis in these patients is suggestive of a pill-induced injury, an autoimmune skin disease involving the esophagus, eosinophilic esophagitis or, less likely, a hypersecretory syndrome or a genotype that confers altered metabolism of PPIs. Refractory reflux syndromes associated with normal endoscopy findings are more problematic to diagnose and further testing may be required, including prolonged 48 h pH testing, impedance measurements (for nonacid reflux), esophageal manometry and gastric function tests. For patients with refractory GERD who do not have esophagitis, possible etiologies include nocturnal gastric acid breakthrough, nonacid GER, missed GER or other diseases such as achalasia, gastroparesis or functional heartburn.

Combination of oxidative stress and steatosis is a risk factor for fibrosis in alcohol-drinking patients with chronic hepatitis C

BACKGROUND AND AIMS

Alcohol and HCV have been shown to interact in stimulating hepatic oxidative damage. Thus, we investigated the contribution of oxidative mechanisms in the progression of chronic hepatitis C (CHC) in alcohol consumers.

METHODS

An increased IgG reactivity against lipid peroxidation-derived antigens was used as the marker for alcohol-induced oxidative damage in 125 CHC patients.

RESULTS

Alcohol intake significantly increased the frequency of the subjects with elevated lipid peroxidation-related IgG. However, no association was evident between oxidative stress markers and the severity of steatosis, necroinflammation, or fibrosis. Multivariate analysis revealed that age (P= 0.014) and hepatic iron content (P= 0.034) were the only independent predictors of fibrosis in these patients. However, the risk of fibrosis in the subjects with both steatosis and oxidative stress-induced immune responses was 6- (OR 6.2, 95% CI 1.2-31.0) and 14-fold (OR 14.6, 95% CI 3.1-68.1) higher than in the subjects with steatosis alone or without steatosis, respectively. Multivariate analysis confirmed that the combination of steatosis and oxidative stress (P= 0.045) was, together with age (P= 0.021) and hepatic iron content (P= 0.027), an independent risk factor for fibrosis in CHC patients with alcohol intake.

CONCLUSIONS

These results demonstrate that oxidative stress interacts with steatosis to promote the progression of CHC in alcohol-consuming patients.

Effects of age on the gastroesophageal junction, esophageal motility, and reflux disease

BACKGROUND & AIMS

The prevalence of complicated gastroesophageal reflux disease (GERD) increases with age; however, the mechanism by which this occurs is uncertain. This study assessed (1) whether physiologic degradation of the gastroesophageal junction and esophageal motility occurs with aging, and (2) whether these effects are associated with increased esophageal acid exposure and reflux symptoms in the elderly.

METHODS

Retrospective study of 1307 patients referred for investigations of reflux symptoms (median age, 49 years; range, 15-92 years) was conducted. Manometry assessed LES pressure, LES length, and esophageal peristalsis. Ambulatory pH studies assessed esophageal acid exposure (% time pH <4) during a period of 24 hours; reflux symptoms were assessed by validated questionnaire.

RESULTS

On multivariate regression, esophageal acid exposure was associated independently with decreasing LES pressure (P < .0001) and abdominal LES length (P < .0004). Dysmotility exacerbated reflux in the recumbent position (P < .004). Acid exposure increased with age (P < .0001), a 1.1%/24 hours (95% confidence interval, 0.4%-1.4%) increase in acid exposure every decade (more pronounced in the recumbent position). The age-related increase in acid exposure was associated independently with decreasing abdominal LES length (P < .001) and increasing dysmotility (P < 0.01). Reflux symptoms increased with acid exposure (P < .001); however, at any given level of exposure, symptom severity was less in the elderly (P < .006).

CONCLUSIONS

Age was associated with an increase in esophageal acid exposure; however, the severity of reflux symptoms reduced with age. These changes were associated with progressive decrease in abdominal LES length and esophageal motility. Increasing GERD severity in the elderly is related to degradation of the gastroesophageal junction and impaired esophageal clearance.

Review article: The measurement of non-acid gastro-oesophageal reflux

BACKGROUND

Oesophageal pH monitoring has been used for three decades to study gastro-oesophageal reflux, but it does not allow detection of non-acid reflux episodes.

AIM

To discuss the techniques by which non-acid reflux can be measured and to evaluate the clinical relevance of such measurements.

METHODS

Review of the literature on non-acid reflux monitoring.

RESULTS

Ambulatory oesophageal impedance monitoring (using a catheter with ring electrodes) allows one to detect all types of gastro-oesophageal reflux, acid as well as non-acid. Measurement of intra-oesophageal bilirubin concentration also detects reflux irrespective of the pH, but only when there is bilirubin in the gastric juice and technical short-comings limit the applicability of this technique. In untreated subjects, about 50% of reflux episodes are non-acid (nadir pH > 4). In patients on acid inhibition, up to 95% of reflux episodes are non-acid. Treatment with an acid inhibitor leads to a significant decrease in the incidence of acid reflux episodes, but not to a reduction in the total number of reflux episodes. This shift is associated with a shift in symptoms from heartburn to regurgitation. With impedance monitoring, the temporal association between symptoms that persist during inhibition of acid secretion and non-acid reflux events can be demonstrated. In a proportion of patients with chronic cough, the coughing episodes are preceded by non-acid reflux.

CONCLUSIONS

Intraluminal impedance monitoring of gastro-oesophageal reflux is a feasible technique, which provides clinically important information about the relationships between symptoms and non-acid reflux events.

Clinical trial: persistent gastro-oesophageal reflux symptoms despite standard therapy with proton pump inhibitors - a follow-up study of intraluminal-impedance guided therapy

BACKGROUND

Persistent gastro-oesophageal reflux disease (GERD), despite proton pump inhibitor (PPI) therapy, is a common problem. Combined pH/impedance monitoring (pH/MII) enables detection of reflux episodes. Aim To identify patients with objective episodes of persistent reflux and second, to evaluate the effect of modified therapy based on the results of pH/MII.

METHODS

In all, 143 patients were examined with pH/MII because of GERD-symptoms resistant to PPI-therapy. Patients with pathological pH/MII (group 1) and with normal results (group 2) were identified. Therapy modifications were evaluated after a minimum follow-up of 3 months.

RESULTS

In 56 of 143 (39.1%) patients, pathological findings in pH/MII were identified. Therapy was escalated in 33/52 patients (group 1) and in 30/71 patients (group 2). Escalating therapy led to symptomatic relief in 90.9% of the patients in group 1 and 43.3% of the patients in group 2 (P < 0.001).

CONCLUSIONS

GERD symptoms refractory to PPI-therapy could be objectively identified with pH/MII in almost 40% of all patients. Furthermore, escalating anti-reflux therapy if pH/MII was pathological is associated with a significantly higher rate of successful treatment compared to the patients with normal findings. Therefore, pH/MII facilitates a more focussed therapeutical approach to patients with PPI-resistant GERD.

Proton-pump inhibitor therapy in patients with gastro-oesophageal reflux disease: putative mechanisms of failure

Proton-pump inhibitor (PPI) failure in gastro-oesophageal reflux disease (GORD) patients has become the main reason for referral of these patients to gastroenterology specialists. It is estimated that 30% of GORD patients requiring a PPI once daily will experience treatment failure. Patients with non-erosive reflux disease are the most common GORD-related group in which once-daily PPI therapy fails. Various mechanisms have been suggested to underlie PPI failure in GORD patients. The most pertinent include weakly acidic reflux, duodenogastro-oesophageal reflux, visceral hyperalgesia, delayed gastric emptying, psychological co-morbidity and concomitant functional bowel disorders, as well as others. Because of the importance of PPI failure as a target for future drug development, further understanding of the most relevant underlying mechanisms is needed.

Prospective study examining the impact of multichannel intraluminal impedance on antireflux surgery

BACKGROUND

Reflux monitoring using combined multichannel intraluminal impedance (MII) and pH-metry increases the sensitivity for identifying gastroesophageal reflux episodes. The likelihood of a positive symptom index (SI) for patients with reflux disease (gastroesophageal reflux disease [GERD] or nonerosive reflux disease [NERD]) receiving proton pump inhibitor (PPI) treatment has been used to select candidates for antireflux surgery. Little is known about the advantages of MII-pH monitoring compared with pH monitoring alone for evaluating GERD/NERD patients off PPI treatment considered as candidates for antireflux surgery or for assessing changes in MII-pH-detected reflux episodes after antireflux surgery. This study aimed to determine the additional value of MII over pH-metry alone for patients off PPI treatment before and after antireflux surgery.

METHODS

For this study 12 patients (4 women and 8 men; mean age, 45 years; range, 27-74 years) were evaluated using ambulatory MII-pH monitoring before and 3 months after mesh-augmented hiatoplasty. Reflux events were identified by MII-pH (A) and pH-metry (B) as patients recorded symptoms on a data logger. For each symptom, a symptom index was calculated for reflux events identified by MII-pH and by pH-monitoring alone.

RESULTS

Preoperatively, MII-pH monitoring identified 71.9 +/- 8.4 reflux episodes, whereas pH monitoring identified only 51.0 +/- 7.8 (p < 0.05). Postoperatively, MII-pH monitoring identified 35.5 +/- 6.6 reflux episodes, whereas pH monitoring identified only 19.6 +/- 4.7 (p < 0.05). The pre- and postoperative symptom index for MII-pH monitoring was higher than pH monitoring (preoperative 91.7% vs 25%, p = 0.006; postoperative 50% vs 16.7%, p = 0.012).

CONCLUSION

Combined MII-pH-metry improves the pre- and postoperative assessment of GERD patients off PPI and results in a higher symptom-reflux association.

New technologies for the evaluation of esophageal motility disorders: impedance, high-resolution manometry, and intraluminal ultrasound

New technologies have been introduced for studying esophageal function, including intraluminal impedance and ultrasound, whereas conventional techniques, such as manometry, have undergone substantial upgrades because of advances in transducer technology, computerization, and graphic data presentation. Although these techniques provide both novel and more detailed information regarding esophageal function, it is still unclear whether they have improved the ability to diagnose and treat patients more effectively. Regardless, they are innovative research tools and they have added substantially to the understanding of the pathophysiology of dysphagia and esophageal motor dysfunction. This article describes the technical aspects of each of these technologies and the potential benefits they offer over conventional techniques for the evaluation of esophageal motor diseases.

The many manifestations of gastroesophageal reflux disease: presentation, evaluation, and treatment

Gastroesophageal reflux disease (GERD) is a common problem that is expensive to diagnose and treat. The disease is increasing in prevalence in the Western world, with important risk factors being obesity and the eradication of Helicobacter pylori. Heartburn and acid regurgitation are classic symptoms of GERD, but their sensitivity is poor. Ambulatory esophageal pH testing is the most sensitive test for GERD, whereas endoscopy is the most specific test. Medical treatment with proton pump inhibitors (PPIs) has revolutionized the treatment of GERD and its complications, but long-term side effects do exist. Laparoscopic anti-reflux surgery and PPIs have similar efficacy in the few available long-term trials. This article reviews the presentation, evaluation, and treatment of GERD.

Gastrooesophageal reflux disease

Gastrooesophageal reflux disease, GERD, is a common problem which is expensive to diagnose and treat. The disease is increasing in prevalence in the Western world with important risk factors being obesity and the eradication of Helicobacter pylori. Increasing research points to transient LES relaxation and spatial separation of the diaphragm and LES (hiatal hernia in chest) being the critical mechanisms of acid reflux. Heartburn and acid regurgitation are classic symptoms of GERD, but their sensitivity is poor. Ambulatory oesophageal pH testing is the most sensitive test for GERD, while endoscopy is the most specific test. Medical treatment with PPIs has revolutionized the treatment of GERD and its complications, but long-term side effects do exist. Laparoscopic antireflux surgery and PPIs have similar efficacy in the few available long-term trials. Currently, endoscopic treatments for GERD should not be a clinical alternative outside of research trials. New drug therapies should be directed at modulating transient LES relaxation.

Review article: the pathophysiology of gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease (GERD) is a common condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications.

AIM

To review the current knowledge on the underlying factors contributing to GERD, with particular emphasis on the most recent research.

METHODS

Literature searches were conducted in Medline and EMBASE. The abstracts from recent large congresses were also reviewed to ensure coverage of the latest findings.

RESULTS

The pathophysiological factors causing GERD can be split into those inducing greater exposure of the oesophagus to stomach contents, and those that provide increased perception of reflux or increased mucosal damage. Transient lower oesophageal sphincter relaxations, which are likely to be triggered by gastric distension, appear to be a key physiological cause of GERD. Excessive reflux may also be provoked by impaired oesophageal or gastric clearance mechanisms. Pre-epithelial, epithelial and post-epithelial defences all normally protect the oesophagus from injury, and may be compromised in individuals with GERD. Heartburn could also be caused by oesophageal hypersensitivity as a result of visceral neural pathway dysfunction.

CONCLUSION

The pathophysiology of GERD is multifactorial, and abnormalities in the gastro-oesophageal junction, the stomach, the oesophagus and the nervous system may all contribute to this disease state.

Gastro-oesophageal reflux disease: oesophageal impedance versus pH monitoring

Gastro-oesophageal reflux occurs frequently during the first months of life. Infants receive frequent milk feeds, and because milk is a potent buffer of gastric acidity, oesophageal impedance should detect more reflux than pH recording. Indeed, impedance has the advantage over pH monitoring of being independent of pH, and as a consequence, of being better adapted to measure reflux during postprandial periods when reflux is buffered and to detect symptoms associated with non-acid or weakly acid reflux episodes. Numerous episodes are detected by one of these techniques (pH monitoring or impedance) in children. Most studies using the impedance technique consider very small numbers of patients, and there are few reports linking data from diagnostic impedance procedures to clinical outcome in symptomatic patients. Data suggesting that impedance does offer a clear-cut benefit in paediatric clinical practice are missing. The high cost of the material and the investment in time necessary for interpretation of the recording, remains a handicap. It is mandatory, despite ethical difficulties, to obtain normal ranges for intraluminal impedance monitoring.

CONCLUSION

As pH monitoring is part of impedance technology, it is likely that the latter will replace pH monitoring despite the current lack of scientific evidence demonstrating a relation between symptoms, oesophageal damage or response to reflux treatment and impedance-pH results.

Developments in pathogenesis and diagnosis of gastroesophageal reflux disease

PURPOSE OF REVIEW

Although gastroesophageal reflux is a common disorder, diagnosis is still imprecise. Moreover, its pathogenesis is incompletely understood. This review summarizes recent progress in diagnosis and our understanding of the pathogenesis of gastroesophageal reflux disease.

RECENT FINDINGS

Recent studies have focused on the pattern of reflux in the distal esophagus, just above the esophago-gastric junction, challenging its importance on the genesis of reflux symptoms. New techniques, such as impedance, could improve the diagnostic yield, especially in patients with nonacid reflux. Esophageal sensitivity and motility, transient lower esophageal sphincter relaxations, and hiatus hernia are important pathogenic mechanisms of reflux disease. Studies showed that obesity plays a role in the pathogenesis of reflux symptoms; a disruption of the esophago-gastric junction (leading to hiatus hernia) could allow reflux to occur. The association between reflux (particularly nonacid) and extraesophageal manifestations of gastroesophageal reflux disease has been further evaluated.

SUMMARY

Improvement of diagnostic techniques and better understanding of the pathogenesis of reflux may lead to new or better therapeutic modalities. Our understanding of some of the risk factors for reflux has been increased. Extra-esophageal manifestations and their association with gastroesophageal reflux are still a very controversial and promising area of research.

Medical therapy of gastroesophageal reflux disease

PURPOSE OF REVIEW

Proton pump inhibitors remain the mainstay of medical therapy in gastroesophageal reflux disease. Despite their increasing use, up to 40% of patients are not fully satisfied with their antireflux therapy. Recent data on efficacy and safety are reviewed and causes of failure are discussed.

RECENT FINDINGS

Several randomized studies and a metaanalysis have shown marginal differences in efficacy between various proton pump inhibitor regimens. In subgroups, however, such as severe esophagitis, esomeprazole may be superior. Poor compliance is one of the main causes of failure. Nonacid reflux is likely to play an important role, especially in patients with regurgitation or cough persisting on therapy. Genetic polymorphisms involved in proton pump inhibitor metabolism, Helicobacter pylori infection or nocturnal acid breakthrough during therapy are probably less important than initially suspected. Recent pharmacological developments include new proton pump inhibitor isomers, potassium competitive acid blockers and inhibitors of transient lower esophageal sphincter relaxations.

SUMMARY

There are still important unmet needs in the treatment of gastroesophageal reflux disease. Optimizing acid control is unlikely to improve the condition of the majority of patients with incomplete proton pump inhibitor response. Inhibition of transient lower esophageal sphincter relaxations remains the major pharmacological target for future drug development.

Laryngopharyngeal reflux and chronic sinusitis

In patients with chronic and recurrent sinusitis, laryngopharyngeal reflux disease may play a significant role. Laryngopharyngeal reflux disease differs from gastroesophageal reflux disease in the extent of reflux (into the hypopharynx and above) as well as timing (occurring more often when the patient is upright). Most patients are unaware of the extent of their symptoms, and diagnostic tools such as pH probe, multichannel intraluminal impedance, and manometry are required for adequate diagnosis. Although therapy with lifestyle modification and acid-suppressive agents may improve reflux in the majority of patients, for many with persistent symptoms, endoscopic or surgical intervention is required to reduce reflux successfully.

The patient with GORD and chronically recurrent problems

Treatment of gastro-oesophageal reflux disease (GORD) by means of gastric acid secretion inhibition usually is successful. When symptoms persist despite adequate treatment, correctness of the diagnosis of GORD should be questioned. Quite often dyspeptic symptoms are erroneously interpreted as GORD symptoms. Other causes of treatment failure are insufficient acid suppression and oesophageal hypersensitivity. In the management of patients with persistent symptoms oesophageal pH and impedance monitoring are useful techniques. These may provide answers to the question whether the symptoms are reflux-related and whether acid secretion is adequately suppressed.

Review article: acidity and volume of the refluxate in the genesis of gastro-oesophageal reflux disease symptoms

BACKGROUND

A number of mechanisms, other than acid reflux, may be responsible for the symptoms of gastro-oesophageal reflux disease.

AIM

To assess the importance of non-acid reflux mechanisms.

METHODS

This review is based on presentations and discussion at a workshop, where specialists in the field analysed data relating to these mechanisms.

RESULTS

Weakly acidic reflux, pH (4-7), detected with impedance-pHmetry is associated with regurgitation and atypical gastro-oesophageal reflux disease symptoms. It is not clear whether pepsin and trypsin can elicit symptoms, but bile can elicit heartburn. The magnitude of reflux-induced oesophageal distension can be determined by high frequency ultrasonography and is not reduced by proton pump inhibition, suggesting that persisting symptoms 'on' a proton pump inhibitor may still be due to oesophageal distension by non-acidic reflux. Exaggerated longitudinal muscle contraction can induce non-acid-related heartburn. Preliminary studies showed a positive effect of baclofen, surgery or endoscopic procedures to reduce weakly acidic reflux.

CONCLUSION

Mechanisms other than acid reflux are involved in some of the symptoms of gastro-oesophageal reflux disease. Controlled outcome studies are needed to clarify their roles and the indications for antireflux procedures in patients with persistent symptoms whilst 'on' a proton pump inhibitor.

Improved diagnosis of gastro-oesophageal reflux in patients with unexplained chronic cough

BACKGROUND

Symptoms, oesophageal pHmetry and proton pump inhibitor treatment are used for diagnosing gastro-oesophageal reflux-related cough. Weakly acidic reflux is now increasingly associated with reflux symptoms such as regurgitation or chest pain.

AIM

To study the association between weakly acidic reflux and cough in a selected, large group of patients with unexplained chronic cough.

METHODS

A total of 100 patients with chronic cough (77 'off' and 23 'on' a proton pump inhibitor) were studied using impedance-pHmetry for reflux detection and manometry for objective cough monitoring. Symptom Association Probability (SAP) Analysis characterized the reflux-cough association.

RESULTS

Acid reflux could be a potential mechanism for cough in 45 patients (with either heartburn, high acid exposure or +SAP for acid reflux). Weakly acidic reflux could be a potential mechanism for cough in 24 patients (with either increased oesophageal volume exposure, increased number of weakly acidic reflux or +SAP for weakly acidic reflux). Reflux could not be identified as a potential mechanism for cough in 31 patients.

CONCLUSION

A positive association between cough and weakly acidic reflux was found in a significant subgroup of patients with unexplained chronic cough. Impedance-pH-manometry identified patients in whom cough can be related to reflux that would have been disregarded using the standard diagnostic criteria for acid reflux.

Cell proliferation of squamous epithelium in gastro-oesophageal reflux disease: correlations with clinical, endoscopic and morphological data

BACKGROUND

The microscopic assessment of squamous epithelium lesions in gastro-oesophageal reflux disease (GERD) is subjective. The Ki67 nuclear antigen expressed by proliferating cells provides an objective measure of regeneration in the squamous epithelium.

AIM

To evaluate Ki67 expression in GERD patients and controls, in comparison with histological lesions, pH-metry and endoscopic data.

METHODS

Eighty-seven patients with GERD symptoms and 20 symptom-free controls underwent endoscopy and 24-h pH monitoring. Oesophageal biopsies (4 cm, 2 cm and Z-line) were stained with Ki67/MIB-1 antibodies; the Ki67-positive nuclear area was assessed with an image analysis system and expressed as percentage of the whole epithelial area (Ki67-%).

RESULTS

Ki67-% was significantly higher in 32 patients with erosive oesophagitis, 44 endoscopy-negative GERD and 11 patients with functional heartburn than in controls (P = 0.0001). Both controls and patients showed a progressive increase in Ki67-% from 4 cm to the Z-line (P < 0.0001). Ki67-% showed a significant correlation with other conventional histological lesions (P ranged between 0.0151 and <0.0001).

CONCLUSIONS

Ki67 evaluation provides quantitative and objective data on squamous epithelium proliferative activity. This marker can be applied in the distinction of endoscopy-negative GERD from healthy controls.

ACG practice guidelines: esophageal reflux testing

Investigations and technical advances have enhanced our understanding and management of gastroesophageal reflux disease. The recognition of the prevalence and importance of patients with endoscopy-negative reflux disease as well as those refractory to proton pump inhibitor therapy have led to an increasing need for objective tests of esophageal reflux. Guidelines for esophageal reflux testing are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee and approved by the Board of Trustees. Issues regarding the utilization of conventional, catheter-based pH monitoring are discussed. Improvements in the interpretation of esophageal pH recordings through the use of symptom-reflux association analyses as well as limitations gleaned from recent studies are reviewed. The clinical utility of pH recordings in the proximal esophagus and stomach is examined. Newly introduced techniques of duodenogastroesophageal reflux, wireless pH capsule monitoring and esophageal impedance testing are assessed and put into the context of traditional methodology. Finally, recommendations on the clinical applications of esophageal reflux testing are presented.