Generation of dyspeptic symptoms by direct acid infusion into the stomach of healthy Japanese subjects

Objective The relationship between acid and dyspeptic symptoms has not been fully understood. Aim To investigate the type and severity of dyspeptic symptoms induced by direct acid infusion into the stomach of Japanese healthy subjects. Methods This was a multi-centre, cross-over, randomized, double-blind study in 27 healthy subjects ( mean age 27). Each fasted subject received two tests with 150 mL of 0.1 mol/L hydrochloric acid infusion (15 mL/min for 10 min) and the same volume of pure water infusion. The type and severity of symptoms were assessed by a 10 cm visual analogue scale administered every 2 min up to 30 min. Results Various symptoms were reported after both acid and water infusions. Most of the symptoms were more severe after acid infusion compared with water infusion (acid vs. water: discomfort 1.8 +/- 0.4 vs. 0.5 +/- 0.1, pain 0.6 +/- 0.3 vs. 0.1 +/- 0.1, reflux 1.0 +/- 0.3 vs. 0.3 +/- 0.1 and satiety 1.1 +/- 0.4 vs. 0.2 +/- 0.1). The area under curve for dysmotility like symptoms ( heavy feeling in the stomach, bloating, nausea or feeling sick, and belching) was significantly higher in acid infusion, and symptoms continued after infusion of the acid. Conclusion Acid induced into stomach induced dysmotility-like predominant dyspeptic symptoms in Japanese healthy control subjects, demonstrating the possible importance of acid in symptom generation.