Effect of pharyngeal water stimulation on esophageal peristalsis and bolus transport

Sensory stimuli originating from the pharynx inhibit esophageal peristalsis induced by a dry swallow. Our aims were to determine the effect of these stimuli on esophageal bolus transport and esophageal peristalsis induced by swallowing different volumes of liquid and semisolid boluses. We studied nine healthy volunteers age 35 ± 4 yr in the supine position by intraluminal esophageal manometry as well as concurrent videofluoroscopy and manometry. In all subjects progression of peristalsis induced by swallowing of different volumes of water and mashed potato boluses was inhibited at all sites by pharyngeal water injection. Threshold volume for inhibition of the peristalsis induced by swallows of 5 and 10 ml of water was similar but significantly higher compared with dry swallows (P < 0.05). Pharyngeal water injection invariably halted transit of the barium boluses through the esophagus. Sensory impulses originating from the pharynx 1) inhibit esophageal bolus transit and 2) are capable of overcoming the facilitating effect of a liquid bolus on the swallowing apparatus. This phenomenon may explain the mechanism of some of the failed esophageal peristalsis observed in clinical practice.