Spontaneous swallowing rate and emotional state. Possible mechanism for stress-related gastrointestinal disorders.

Excessive spontaneous swallowing has been associated with a variety of common gastrointestinal symptoms including abdominal pain, heartburn, and bloating and may contribute to disorders such as hiatus hernia, duodenal ulcer, and irritable bowel syndrome. The present study investigated the hypothesis that changes in emotional state alter spontaneous swallowing rate. Subjects were 38 generally healthy undergraduates assigned to either a pleasant low arousal, neutral, or aversive high arousal condition. Each experimental session was divided into 30-min baseline and arousal manipulation periods. Spontaneous swallowing rate increased significantly with emotional arousal: for low, neutral, and high arousal groups, means were 7.9 +/- 1.9 (SE), 15.8 +/- 2.4, and 23.7 +/- 3.6 swallows/30 min, respectively. Other physiological and self-report measures, used to check the effectiveness of the arousal manipulation, varied appropriately with experimental procedures. These results indicate that changes in emotional state alter spontaneous swallowing rate in generally healthy individuals. Further research with patients is needed to establish whether stress-induced increases in swallowing rate produce or exacerbate clinically significant gastrointestinal symptomatology.