The Effect of the LEFT Smartwatch App as Sleep Positional Therapy for Nocturnal Gastroesophageal Reflux Symptoms.

Inclusion Criteria: * Written informed consent. * Both male and female patients will be included. * Age 18 years or older. * Symptoms of heartburn and/or acid regurgitation during at least three nights a week. * A total reflux symptom score ≥8 (measured through the GERDQ questionnaire score). * Able to wear the Apple Watch on the left wrist. Exclusion Criteria: * Complete PPIs non-responders. * Nightshift workers * Surgery of the esophagus or stomach. * Regular use of sleep medication (benzodiazepines) or medication which affect gastrointestinal motility (e.g. prokinetics or opioids) that cannot be stopped during the duration of the trial. * Severe and clinically unstable concomitant disease (e.g. liver, cardiovascular or lung disease, neurological or psychiatric disorders, cancer or AIDS and other endocrine disorders) * Patients with obstructive sleep apnea or esophageal motility disorders. * Pregnant or lactating women.