Esophageal body motor response to reflux events: secondary peristalsis.

The esophageal body is a major component of the antireflux mechanism. Disruption of esophageal peristalsis affects both volume clearance and delivery of swallowed saliva to the distal esophageal body. The esophageal body responds to reflux by an increase in primary peristalsis through stimulation of swallowing and secondary peristalsis through esophageal distension. Primary peristalsis is the most common motor event after reflux and accounts for up to 90% of initial and subsequent motor activity. Secondary peristalsis is uncommon but may be important during sleep when swallowing is relatively suppressed. Some patients with reflux disease, particularly those with severe esophagitis, exhibit impaired esophageal responses to reflux. It is likely that this impairment prolongs acid clearance and may also influence the proximal extent of the refluxate within the esophageal body.