Figure 8 - Three different mechanisms of LES incompetence in gastroesophageal reflux.

a; The LES may be hypotensive causing free reflux of acid into the esophagus. b; The LES barrier may be overwhelmed by increased intragastric pressure. This is often associated with impaired contraction of the diaphragmatic sphincter. c; LES may exhibit frequent reflex transient LES relaxation (TLESR) TLESR is a vagovagal inhibitory reflex that is different from swallowing reflex and is akin to belch reflex. (Source: Dodds WJ et al. N. Engl J Med. 1982;307(25):1547–1552)