Standardization of electrode positioning and composition of meals for long-term intragastric pH metry in man.

In these prospective studies the influence of two different intragastric positions of electrodes and of four different compositions of standardized meals on 24-hour ambulatory pH recording were compared intraindividually in healthy male subjects. Simultaneous pH monitoring in 12 subjects demonstrated a more pronounced postprandial pH elevation in the fundus body compared to the antral area. The intraindividual comparison of an identical diet given on two different days to 10 subjects revealed nearly identical pH profiles. Variations of carbohydrate, protein and fat content of isocaloric meals given in a randomized order did not significantly alter 24-hour intragastric pH profiles. It is concluded from these data that positioning of the pH electrode in the fundus body area is superior to an antral position. 24-hour ambulatory intragastric pH monitoring in man is well reproducible. A strict standardization of the composition of meals is mandatory only for scientific investigations.