Editor,—We read the paper by Sifrimet al (Gut1999;44:47–54) with interest. Transient lower oesophageal sphincter relaxations (TLOSRs) have become widely accepted as the cause of most acid reflux episodes in health and disease. It is also accepted that TLOSRs are involved in the belch mechanism. This paper refutes our assertion that the majority of acid reflux events occur in healthy individuals in association with the venting of gas, based on pressure measurements in ambulant subjects.1 ,2

The current paper has shown that gas can be detected passing out of the stomach during TLOSRs. The authors found that only 18% of TLOSRs were solely gas reflux and nearly 60% of TLOSRs were associated with liquid reflux alone or neither the reflux of liquid or gas. This implies that spontaneous TLOSR occurs commonly and is not initiated by the fundal stretch “belch” mechanism. We wonder what exact teleological reason there can be for such a phenomenon.

The authors would suggest that in control subjects, acid reflux episodes are more common than simple belching. This seems contrary to …