Which condition is characterized by failure of oesophageal peristalsis and relaxation of the lower oesophageal sphincter?

Achalasia is characterized by the failure of esophageal peristalsis and the inability of the lower esophageal sphincter (LES) to relax properly. In this condition, the esophagus is unable to effectively move food down into the stomach due to a lack of coordinated muscle contractions. Additionally, the LES fails to open when swallowing occurs, leading to obstruction. This results in symptoms such as dysphagia (difficulty swallowing), regurgitation, and chest pain.

Dysphagia, while a symptom of many esophageal conditions, refers specifically to the difficulty in swallowing and does not describe any underlying motor dysfunction or sphincter relaxation mechanism. Gastroesophageal reflux disease (GERD) is related to the improper closure of the LES, allowing stomach contents to flow back into the esophagus, which is different from the failure to relax. Esophageal varices refer to enlarged veins in the esophagus, typically caused by liver disease, and are not directly related to peristalsis or sphincter relaxation. Thus, achalasia is distinct and accurately reflects the defined characteristics of failure in both peristalsis and sphincter relaxation.