Effect of carbonated water on gastric emptying and intragastric meal distribution

Carbonated water has long been advocated to relieve dyspeptic symptoms, suggesting that it may alter gastric motility via gastric distension. This study aimed to determine the effect of carbonated water on gastric emptying of a radiolabeled mixed meal in eight healthy volunteers. Meal emptying and its distribution within the stomach were assessed with carbonated and still water in a crossover study. Emptying of both solid and liquid, including the duration of the lag phase, was identical for both drinks. However, the proximal stomach contained a greater proportion of solids (74 +/- 7% vs 56 +/- 8%, P < 0.05) and liquids (43 +/- 5% vs 27 +/- 4%, P < 0.05) with carbonated water as opposed to still water. Retention of the meal within the proximal stomach ended with the lag phase and was likely related to proximal distension. In conclusion, carbonated water did not alter overall gastric emptying but profoundly modified intragastric distribution of the meal.