Evaluation of gastric volume and pH changes in gastroscopy patients using chewing gum and candy: A prospective randomized double-blind study

Background: Whether chewing gum or candy consumption during preoperative fasting affects aspiration risk remains debated. This study investigated the effects of these products on gastric volume and pH, and evaluated procedure difficulty, satisfaction, and fasting-related symptoms. Methods: This randomized, double-blind study enrolled 405 patients scheduled for elective gastroscopy, equally allocated to control, chewing gum, and candy groups. All groups adhered to standard fasting protocols; the chewing gum and candy groups additionally consumed the assigned products within 2 hours of sedation induction. Gastric contents were aspirated and analyzed for volume and pH. Fasting-related symptoms and satisfaction were assessed prior to discharge using a 3-point Likert scale. Results: Baseline characteristics were comparable across groups. Fasting duration was significantly shorter in the chewing gum group ( P = .030). Gastric volume was significantly higher in both intervention groups than in the control group ( P < .001); however, all values remained below the aspiration threshold of 0.5 mL/kg with small effect sizes. No significant between-group differences in gastric pH were observed ( P = .697). Procedure difficulty, satisfaction, and complication rates did not differ across groups. Chewing gum reduced thirst while increasing hunger, whereas candy reduced hunger while increasing thirst (all P < .001). Conclusion: Preoperative chewing gum or candy consumption produced a statistically significant but clinically negligible increase in gastric volume without affecting gastric pH. The distinct effects on fasting-related symptoms suggest that symptom-based product selection may improve patient comfort. These findings indicate that preoperative chewing gum or candy intake does not meaningfully increase the risk of aspiration before endoscopic procedures.