Abstract
The hypothesis has been raised that a dysfunction of the longitudinal oesophageal muscle is the common denominator for pharyngeal and oesophageal dysphagia in patients with hiatal hernia, and that contraction of the longitudinal muscle is a contributing factor for the opening of the upper oesophageal sphincter and for the stiffening of the oesophageal wall when swallowing. Different studies were used to test the implications of this hypothesis. It was concluded that dysfunction of the longitudinal oesophageal muscle, caused by slipping of the distal end through the hiatal canal, can explain oesophageal dysphagia and inadequate opening of the upper oesophageal sphincter.