Frequency of the asymptomatic lower esophageal contractile ring.
D000013:Congenital Abnormalities; D003679:Deglutition; D003680:Deglutition Disorders / Q000209:etiology*; D004935:Esophageal Diseases; D004947:Esophagus / Q000002:abnormalities*; D006801:Humans; D009119:Muscle Contraction
ABNORMALITIES; DEGLUTITION DISORDERS/etiology and pathogenesis; ESOPHAGUS/abnormalities