Transmucosal potential difference; diagnostic value in gastro-oseophageal reflux.

Nineteen patients with symptoms of upper gastrointestinal disease were assessed by endoscopy. Transmucosal potential difference (PD) in the lower oesophagus was recorded and suction biopsy specimens were obtained from the site of measurement and examined by light microscopy after haematoxylin and eosin staining. In 10 patients with normal histology, mean PD was--14.4 mV (SEM +/- 0.4 mV), whereas in nine patients with histological changes of reflux mean was +9.4 mV (SEM +/- 3.0 mV). In this latter group, polarity of the PD was reversed in all but one case. Good correlation was found between these objective indices of lower oesophageal disease and the presence of symptoms such as dysphagia and heartburn. The visual appearance at endoscopy was less reliable. It is suggested that measurement of PD is a simple, rapid, and sensitive method of detecting the presence of oesophageal mucosal damage.