Esophageal physiology-an overview of esophageal disorders from a pathophysiological point of view.

The esophagus serves the principal purpose of transporting food from the pharynx into the stomach. A complex interplay between nerves and muscle fibers ensures that swallowing takes place as a finely coordinated event. Esophageal function can be tested by a variety of methods, endoscopy, manometry, and reflux monitoring being some of the most important. Regarding pathophysiology, motor disorders, such as achalasia, often cause dysphagia and/or chest pain. Functional esophageal disorders are a heterogeneous group with hypersensitivity as a dominant pathophysiological factor. Gastroesophageal reflux disease often causes symptoms, such as heartburn and regurgitation, and a spectrum of disease, ranging from minimal mucosal damage visible only in the microscope to esophageal ulcers and strictures in the most severe cases. Eosinophilic esophagitis is an immune-mediated condition that can result in significant dysphagia and associated luminal narrowing. In the following, we will provide an overview of the most common esophageal disorders from a combined pathophysiological and clinical view.