A competent lower esophageal sphincter (LES) prevents gastroesophageal reflux disease (GERD) in the setting of increased abdominal pressure. Therefore, we have assessed whether a back support belt causes gastroesophageal reflux (GER). Ten healthy volunteers underwent esophageal manometric studies to locate the LES. Subsequently, each subject underwent two separate 8-hour intra-esophageal pH monitor studies on different days, the first without wearing a back support belt, and the subsequent one wearing a back support belt. A symptom diary and continuous intra-esophageal pH data were obtained during both study periods. The mean LES pressure (LESP) was 14 +/- 3.6 mm Hg without a back support belt and 15.8 +/- 4.3 mm Hg with a back support belt which was not significantly different. There were no significant differences in total episodes of GER, esophageal acid exposure, or any other parameters monitored. Symptoms of GER were the same comparing the back support belt with no back support belt. We conclude that healthy people with normal LESP do not have increased GER as a result of wearing a back support belt.