Reflux Hypersensitivity

Reflux hypersensitivity (RH) is one of the five functional esophageal disorders defined by the Rome IV criteria, alongside functional heartburn, functional chest pain, globus, and functional dysphagia (Shibli and Fass, The Esophagus, 2021). It describes patients who have classic reflux symptoms — heartburn, chest discomfort, or regurgitation — and a normal upper endoscopy, but whose esophageal acid exposure measured on pH testing is actually within the normal physiologic range. What sets reflux hypersensitivity apart is that their symptoms are reliably triggered by individual reflux events, even though the overall amount of reflux is normal (Gyawali and Fass, Gastroenterology, 2018).

In practical terms, the esophagus in these patients has turned up the volume on reflux it should be able to ignore. This is why reflux hypersensitivity is a common and frequently missed explanation for "PPI-refractory reflux." Among patients who do not respond to twice-daily proton pump inhibitor (PPI) therapy, roughly 28–36% are found to have reflux hypersensitivity, and together with functional heartburn these disorders account for most cases of PPI-refractory heartburn (Gyawali and Fass, Gastroenterology, 2018). Recognizing reflux hypersensitivity matters because it changes the entire treatment strategy — away from escalating acid suppression and toward calming the esophageal nerves (Gyawali et al., Gastroenterology, 2026).

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Reflux hypersensitivity is driven by an amplified perception of normal reflux rather than by excess acid (Aziz et al., Gastroenterology, 2016). The underlying mechanisms are shared with other functional esophageal and brain–gut disorders and include:

• Peripheral sensitization — reflux, bile, or trypsin causes low-grade mucosal irritation and impaired mucosal integrity, lowering the firing threshold of esophageal sensory nerves (Fass et al., Nature Reviews Disease Primers, 2021).

• Central sensitization — repeated nociceptive signaling alters how the spinal cord and brain process esophageal sensation, amplifying the signal (Tack and Pandolfino, Gastroenterology, 2018).

• Up-regulated acid-sensing receptors — increased expression of acid-sensitive channels such as TRPV1, plus neurogenic inflammation markers like substance P and its receptor NK1R (Gyawali et al., Gastroenterology, 2026).

• Brain–gut axis dysregulation — autonomic imbalance and the influence of anxiety, depression, and symptom hypervigilance on perception (Gyawali et al., Gastroenterology, 2026).

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• Persistent heartburn or chest pain that only partially responds, or does not respond, to PPI therapy (Gyawali and Fass, Gastroenterology, 2018)

• Normal or near-normal upper endoscopy (no erosive esophagitis or Barrett's) (Aziz et al., Gastroenterology, 2016)

• Coexisting anxiety, depression, hypervigilance, or stress (Gyawali et al., Gastroenterology, 2026)

• Overlap with other brain–gut disorders such as irritable bowel syndrome, functional dyspepsia, and insomnia (Kahrilas et al., Alimentary Pharmacology & Therapeutics, 2025)

• Overlap with established GERD — reflux hypersensitivity can coexist with true reflux disease rather than being mutually exclusive (Shibli and Fass, The Esophagus, 2021)

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Under normal conditions, the esophagus tolerates small amounts of physiologic reflux without producing any sensation. In reflux hypersensitivity, the sensory apparatus of the esophagus — from the mucosal nerve endings to the spinal cord to the brain's processing centers — is sensitized, so that ordinary reflux episodes are perceived as painful heartburn or chest pain (Oldfield et al., The Esophagus, 2021). Impaired mucosal integrity may allow acid and other refluxate to reach sensory nerves more easily, and reduced mucosal impedance (lower mean nocturnal baseline impedance) is seen in these patients compared with functional heartburn (Gyawali et al., Gastroenterology, 2026). Importantly, the esophageal lining itself is not being damaged — endoscopy is normal and there is no progression to erosive disease. The problem is one of perception and signaling, not tissue injury.

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Reflux hypersensitivity is a benign condition in the sense that it does not cause esophageal ulceration, strictures, Barrett's esophagus, or cancer (Aziz et al., Gastroenterology, 2016). The principal "complications" are clinical and quality-of-life related:

• Significant impairment of quality of life and sleep from persistent symptoms (Gyawali et al., Gastroenterology, 2026)

• Unnecessary, escalating acid-suppression therapy when the diagnosis is not recognized (Fass et al., American Gastroenterological Association, 2020)

• Inappropriate antireflux surgery performed on patients without true pathologic reflux, which can fail to relieve symptoms (Gyawali et al., American College of Gastroenterology, 2020)

• Frequent coexisting anxiety and hypervigilance that can perpetuate and amplify symptoms (Gyawali et al., Gastroenterology, 2026)

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• Heartburn — a burning retrosternal sensation, often indistinguishable from classic GERD (Aziz et al., Gastroenterology, 2016)

• Non-cardiac chest pain or chest discomfort (Aziz et al., Gastroenterology, 2016)

• Regurgitation or a sour/bitter taste that correlates with reflux episodes (Gyawali et al., Gastroenterology, 2026)

• Symptoms occurring at least twice a week, present for the prior 3 months with onset at least 6 months earlier (Aziz et al., Gastroenterology, 2016)

• A partial or incomplete response to PPIs — some patients with an acid-sensitive esophagus do improve on PPIs, while those with weakly acidic or non-acid triggers typically do not (Gyawali et al., Gastroenterology, 2026)

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Reflux hypersensitivity is a diagnosis of careful exclusion that requires objective esophageal testing — it cannot be diagnosed on symptoms alone (Gyawali et al., Gastroenterology, 2026). The workup includes:

• Upper endoscopy to confirm a normal esophagus and exclude erosive esophagitis, Barrett's esophagus, and eosinophilic esophagitis (with biopsies) (Aziz et al., Gastroenterology, 2016).

• High-resolution esophageal manometry to exclude major motility disorders such as achalasia, EGJ outflow obstruction, distal esophageal spasm, jackhammer esophagus, and absent peristalsis (Aziz et al., Gastroenterology, 2016).

• Ambulatory reflux monitoring (pH or pH-impedance) demonstrating physiologic acid exposure — acid exposure time (AET) below 4% — combined with a positive symptom–reflux association (Gyawali et al., Gastroenterology, 2026).

• Symptom–reflux association indices — a positive symptom index (SI ≥ 50%) and/or symptom association probability (SAP ≥ 95%) is the feature that distinguishes reflux hypersensitivity from functional heartburn (Katz et al., American College of Gastroenterology, 2022).

The Rome IV diagnostic criteria require all of the following: retrosternal symptoms (heartburn/chest pain); normal endoscopy with no evidence of EoE; absence of major motor disorders; and evidence that symptoms are triggered by reflux events despite normal acid exposure — and notably, a response to acid-suppression therapy does not exclude the diagnosis (Aziz et al., Gastroenterology, 2016). Prolonged wireless pH monitoring is valuable because up to one-third of patients initially labeled functional heartburn on a 24-hour study are reclassified as NERD or reflux hypersensitivity on longer recording (Wu et al., PLoS One, 2024).

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• Non-erosive reflux disease (NERD) — abnormal esophageal acid exposure with a normal endoscopy (the key difference: acid exposure is elevated in NERD, normal in RH) (Fass et al., American Gastroenterological Association, 2020)

• Functional heartburn — normal acid exposure but a negative symptom–reflux association (RH has a positive association; functional heartburn does not) (Katz et al., American College of Gastroenterology, 2022)

• Erosive esophagitis / Barrett's esophagus — excluded by endoscopy (Aziz et al., Gastroenterology, 2016)

• Eosinophilic esophagitis — excluded by esophageal biopsies (Aziz et al., Gastroenterology, 2016)

• Major esophageal motility disorders — achalasia, EGJ outflow obstruction, spasm, jackhammer, absent peristalsis — excluded by manometry (Aziz et al., Gastroenterology, 2016)

• Rumination syndrome and supragastric belching — considered when regurgitation or belching is the only symptom associated with reflux events (Gyawali et al., Gastroenterology, 2026)

• Cardiac chest pain — must be excluded before attributing chest pain to the esophagus (Oldfield et al., The Esophagus, 2021)

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Because reflux hypersensitivity sits at the perception-dominant end of the reflux spectrum, lifestyle strategies focus both on reducing reflux triggers and on down-regulating the brain–gut stress response (Kahrilas et al., Alimentary Pharmacology & Therapeutics, 2025):

• Weight management, avoiding late or large meals, and not lying down within ~3 hours of eating, since even physiologic reflux can trigger symptoms

• Elevating the head of the bed for nighttime symptoms

• Limiting personal trigger foods (alcohol, caffeine, chocolate, peppermint, fatty or spicy foods)

• Smoking cessation

• Stress-reduction techniques, sleep optimization, and addressing hypervigilance, given the strong role of the brain–gut axis (Gyawali et al., Gastroenterology, 2026)

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Treatment begins with reassurance and education that no dangerous or progressive disease is present (Gyawali et al., Gastroenterology, 2026). The therapeutic approach differs fundamentally from classic GERD:

• Acid suppression (PPIs, and potentially PCABs): A trial is reasonable because response may be better than in other functional disorders, and patients with a genuinely acid-sensitive esophagus can improve on standard or high-dose PPIs. However, those with weakly acidic or non-acid triggers often remain refractory (Gyawali et al., Gastroenterology, 2026). H2-receptor antagonists may add an esophageal pain-modulating benefit (Aggarwal and Kamal, Current Gastroenterology Reports, 2020).

• Neuromodulators (the cornerstone): Low-dose tricyclic antidepressants, SSRIs, SNRIs, and gabapentinoids are the mainstay of therapy. A placebo-controlled trial showed citalopram significantly reduced symptoms in reflux hypersensitivity (38.5% still symptomatic vs. 66.7% on placebo; P = .021) (Gyawali et al., Gastroenterology, 2026).

• Psychological / behavioral therapies: Gut-directed cognitive behavioral therapy, hypnotherapy, and biofeedback target the hypervigilance and central sensitization that sustain symptoms (Gyawali et al., Gastroenterology, 2026).

• Antireflux surgery (selected patients only): Surgery may help carefully selected patients — particularly those with a concurrent hiatal hernia and a clearly positive symptom–reflux association — and in a randomized trial, antireflux surgery was superior to medical therapy in patients with PPI-refractory heartburn that included reflux hypersensitivity (Gyawali et al., Gastroenterology, 2026). This is where proper physiologic testing is essential: operating without objective evidence of a reflux trigger risks a poor outcome, whereas a documented positive symptom–reflux association and a repairable anatomic defect identify the patients most likely to benefit. By contrast, a sham-controlled trial of endoscopic radiofrequency therapy showed no benefit (Gyawali et al., Gastroenterology, 2026).

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See a physician if you have frequent heartburn or chest discomfort — particularly if it persists despite over-the-counter or prescription acid-blocking medication — so that the cause can be properly identified rather than simply treated with escalating doses (Fass et al., American Gastroenterological Association, 2020). Any chest pain should be evaluated to rule out a cardiac cause before it is attributed to the esophagus (Oldfield et al., The Esophagus, 2021).

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Seek prompt evaluation — including upper endoscopy — if you develop any alarm symptom: difficulty swallowing, painful swallowing, unintended weight loss, vomiting, gastrointestinal bleeding (vomiting blood or black stools), or unexplained anemia (Katz et al., American College of Gastroenterology, 2022). These features point toward a structural problem rather than a functional one and should never be managed with acid-blocking pills alone. Formal esophageal physiologic testing is especially important before any antireflux surgery is considered, to confirm the diagnosis and avoid operating on symptoms that are not truly reflux-driven (Gyawali et al., American College of Gastroenterology, 2020).

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With an accurate diagnosis and a tailored, often combined approach — reassurance, targeted acid suppression where it helps, neuromodulators, and psychological therapies — most patients achieve meaningful and lasting improvement in symptoms and quality of life (Gyawali et al., Gastroenterology, 2026). Because reflux hypersensitivity can overlap with true GERD, periodic reassessment ensures that any evolving acid-driven component is identified and managed. The long-term key is avoiding the two common errors: indefinitely escalating acid suppression that cannot work on non-acid triggers, and performing antireflux surgery without objective confirmation of a reflux trigger (Fass et al., American Gastroenterological Association, 2020; Gyawali et al., American College of Gastroenterology, 2020).

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Reflux hypersensitivity is a benign, non-progressive condition that does not damage the esophagus or increase the risk of Barrett's esophagus or cancer (Aziz et al., Gastroenterology, 2016). While symptoms can be persistent and frustrating, the outlook for symptom control is good once the correct diagnosis is made and treatment is shifted toward neuromodulation and behavioral therapy rather than ever-higher doses of acid suppression (Gyawali et al., Gastroenterology, 2026). Patients with a genuinely acid-sensitive esophagus often do well with acid suppression, and appropriately selected surgical candidates can achieve durable relief.

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Reflux hypersensitivity is one of the most commonly misdiagnosed causes of "reflux that won't go away," and getting it right requires a foregut specialist who insists on objective esophageal physiologic testing — high-resolution manometry and ambulatory pH-impedance monitoring — before recommending any procedure. Dr. Nestor de la Cruz-Muñoz, MD, FACS, DABOM, brings a comprehensive, evidence-based approach to refractory reflux symptoms, distinguishing true acid-driven disease from functional esophageal disorders and reserving antireflux surgery for the carefully selected patients most likely to benefit — those with a documented positive symptom–reflux association and a repairable anatomic defect such as a hiatal hernia. This diagnostic rigor protects patients from unnecessary operations and delivers better, more durable outcomes.

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