Comprehensive Analysis of the Swallowing Mechanism Using High-resolution Manometry With Impedance

Inclusion Criteria: * age 18-75 years * patients with swallowing difficulties suspected of having a functional oesophageal disorder or patients with clinical signs of extra-oesophageal reflux (Reflux Symptom Index \[RSI\] ≥ 13 or Reflux Symptom Score-12 \[RSS-12\] ≥ 11) signed informed consent Exclusion Criteria: * patients with a diagnosed tumor of the esophagus or upper airway, or with strong clinical suspicion of a tumor of the esophagus or upper airway * severe neurological disease affecting swallowing * pregnancy * surgery involving the head, neck, or esophagus within the last 6 months