Abstract
Background : The pH measurement of fasting gastric juice is often used to investigate acid-related disorders. Grape juice contains anthocyanin pigments that change color according to the pH. The aim of this study was to evaluate the pH of fasting gastric juice with grape juice. Methods : Before the upper endoscopy, pharyngeal anesthesia was achieved with a frozen mixture of viscous lidocaine and grape juice, which the patient licked to ingest. During the upper endoscopy the colors of the gastric juice on the LCD monitor were evaluated. The gastric juice was serially collected and the pH of the gastric juice was evaluated. Results : The colors of the gastric juice were classified into four groups of red, blackish-blue, clear-white and yellow. Red and clear-white groups showed a low pH. The blackish-blue group showed weak acid to neutral pH. The yellow group showed no specific pH. The pH values of each pair of groups except for yellow and clear-white showed significant differences. Conclusions : The pH values of gastric juice are useful to realize the pathophysiology of acid-related disorders. Using this method, in most of cases we can easily determine the approximate intragastric acidity.
