Tutuian et al (Gut 2006;55:584–5) performed high resolution oesophageal manometry in a patient with achalasia and “chest pressure” following swallowing. They observed a sustained increase in intra-oesophageal pressure with maximum pressure at the time of maximal oesophageal shortening. Oesophageal shortening is attributed to longitudinal muscle contraction. The mechanism that they propose for this pressure increase is “pump gun” (after the classic side action firearm first patented in Britain by Alexander Bain in 1854). They also suggest that reduction in oesophageal pressure during this episode is due to oesophageal emptying that clears the oesophagus and results in …