Does lying on the right side increase the rate of gastric emptying?

1. Saline test meals (750 ml., 125 mM-NaCl) were given by tube into the stomachs of five subjects who were either sitting, lying on the left side, or lying on the right side. The gastric contents were recovered at 10 min. The rate of gastric emptying was assessed from the recovery of the original solution, marked with phenol red. 2. The mean volume of this rapidly emptying test solution recovered after 10 min was 215 ml. from subjects lying on the right side and 431 ml. from subjects lying on the left side (P < 0.005) and 308 ml. from the sitting subjects. 3. Similar studies were made with 750 ml. test meals of a solution of glucose monohydrate (100 g/l.) given to the same subjects in the same positions, but the recoveries of this more slowly emptying solution were made at 20 min. 4. There was no statistically significant difference between the volumes recovered when subjects lay on their left sides (589 ml), when they lay on their right sides (555 ml.), and when they were sitting (564 ml.). 5. These results are consistent with posture influencing gastric emptying provided the given meal does not strongly activate duodenal receptors mediating the slowing of gastric emptying.