Gastrointestinal Motility and Reflux Disorders

Gastrointestinal motility encompasses the coordinated contraction of smooth muscle along the digestive tract, facilitating the transit of ingested material from the oropharynx to the colon. Central to this process is peristalsis, the sequential wave‐like contraction that propels luminal contents, and the regulated opening of sphincters such as the lower oesophageal sphincter (LES). Disruption of these mechanisms may lead to motility disorders such as achalasia, characterised by failure of the LES to relax and impaired oesophageal peristalsis, or to reflux disorders including gastro‐oesophageal reflux disease (GORD) and laryngopharyngeal reflux, where retrograde flow of gastric contents causes mucosal injury, inflammation and extra‐oesophageal manifestations. The pathophysiology of these conditions reflects a complex interplay between neural, immunological and mechanical factors. Diagnostic modalities range from high‐resolution manometry, which maps pressure topography throughout the oesophagus, to impedance–pH monitoring, which quantifies reflux episodes. Therapeutic approaches include pharmacological acid suppression, endoscopic interventions such as per‐oral endoscopic myotomy and surgical fundoplication, each requiring individualisation according to motility profiles, symptom severity and patient comorbidities. Globally, reflux disorders constitute a significant health burden, contributing to diminished quality of life, increased healthcare utilisation and potential complications such as Barrett’s oesophagus and adenocarcinoma. Advances in molecular profiling, diagnostic precision and minimally invasive therapies continue to refine management strategies and to elucidate the underlying mechanisms of motility and reflux disorders.

Research from Nature Portfolio

Single‐cell transcriptomics of tissue from patients with achalasia has revealed distinct immune cell populations within the lower oesophageal sphincter. In particular, C1QC+ macrophages that resemble central nervous system microglia and tissue‐resident memory T cells (TRM) were found concentrated around the myenteric plexus, displaying a neurodegenerative phenotype and altered activation signatures that intensify with disease progression. This work highlights the role of local immune‐mediated ganglionitis in myenteric neuron loss. A global systematic review and meta‐analysis of gastro‐oesophageal reflux disease prevalence and risk factors pooled data from over a hundred studies, revealing a global pooled prevalence nearing 14%, with significant regional variability. Age, obesity, diet and smoking emerged as key modifiers of individual risk, offering a framework for targeted prevention strategies. Foundational consensus statements have also updated the indications for modern oesophageal physiological testing, standardising interpretation of high‐resolution manometry and reflux monitoring to improve diagnostic accuracy and guide therapy.

Gastrointestinal Motility and Reflux Disorders publication trend

The graph below shows the total number of articles in gastrointestinal motility and reflux disorders across all publications each year (not limited to Nature Index journals).

Technical terms

Peristalsis: Coordinated contraction and relaxation of gastrointestinal smooth muscle that propels contents along the digestive tract.

Lower oesophageal sphincter (LES): A specialised ring of smooth muscle at the gastro‐oesophageal junction that regulates passage of food and prevents reflux.

Achalasia: A primary oesophageal motility disorder characterised by aperistalsis of the oesophageal body and impaired LES relaxation.

Gastro‐oesophageal reflux disease (GORD): A condition in which reflux of gastric contents causes troublesome symptoms and/or complications.

High‐resolution manometry: A diagnostic test that records pressure along the oesophagus at multiple closely spaced sensors to evaluate motility patterns.

Per‐oral endoscopic myotomy (POEM): A minimally invasive endoscopic procedure that divides the LES muscle fibres to alleviate obstruction in achalasia.

Tissue‐resident memory T cells (TRM): A subset of long‐lived T lymphocytes that reside within tissues and contribute to local immune surveillance and inflammation.

References

1. The Efficacy of Peroral Endoscopic Myotomy vs Pneumatic Dilation as Treatment for Patients With Achalasia Suffering From Persistent or Recurrent Symptoms After Laparoscopic Heller Myotomy: A Randomized Clinical Trial. Gastroenterology (2023).
2. A single-cell transcriptional landscape of immune cells shows disease-specific changes of T cell and macrophage populations in human achalasia. Nature Communications (2023).
3. Global Prevalence and Risk Factors of Gastro-oesophageal Reflux Disease (GORD): Systematic Review with Meta-analysis. Scientific Reports (2020).
4. Laryngopharyngeal Reflux: Diagnosis, Treatment, and Latest Research. International Archives of Otorhinolaryngology (2013).
5. Evidence-based clinical practice guidelines for gastroesophageal reflux disease 2021. Journal of Gastroenterology (2022).
6. Advances in the physiological assessment and diagnosis of GERD. Nature Reviews Gastroenterology & Hepatology (2017).
7. The global, regional, and national burden of gastro-oesophageal reflux disease in 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. The Lancet Gastroenterology & Hepatology (2020).