ABSTRACT
The physiology of low esophagus has largely benefited from the development of functional exploration techniques. Esophagian continence causes the intervention of anatomic factors. The lower sphincter of the esophagus [LS.e] is the most important physiological element. Its regulation is complicated, multifactorial [nervous, hormonal, pharmacologic, alimentary]. The motoricity of low esophagus is studied in rest, then during the deglutition. The LSO incurs the action of different forces which exercise themselves on the low esophagus and the diaphragm. The integration of these forces realizes a balance, ranked to an equation of the continence. Other factors intervene in the gastroesophagian reflux, these are: the gastric drain and secretion and above all the clearance of esophagus whose good functioning is the security of the integrity of the esophagian mucosa