Twenty-four-hour lower esophageal pH monitoring and the lower esophageal sphincter.
D000005:Abdomen; D004943:Esophagogastric Junction / Q000502:physiology / Q000503:physiopathology*; D004947:Esophagus / Q000033:anatomy & histology; D005764:Gastroesophageal Reflux / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011312:Pressure