Transient lower esophageal sphincter relaxations (tLESr) are the main mechanism of gastro-oesophageal reflux disease. They occur without any deglutition in patients but also in healthy volunteers. They are induced by meal.

The gold standard to detect tLESr is esophageal manometry using perfused Dentsleeve probe.

Esophageal high resolution manometry with solid state sensors was developed in the 90s. The examination is easier and more accurate than perfused manometry. The aim of this study is to validate in healthy volunteers the use of high resolution manometry (Sierra Scientific Instruments, California CA) to detect tLESr.

Inclusion Criteria:

1. Male or Female between 18 and 60 years
2. Subject without typical or atypical symptoms of gastro-esophageal reflux disease (heartburn, regurgitation, epigastric pain, chest pain, chronic cough, pharyngeal pain)
3. Subject without any medication (except oral contraception)
4. Subject without previous digestive surgery history (except appendicectomy)
5. Capability to pass manometric probes through each nostril
6. Subject with health insurance
7. Written informed consent
8. No participation to another study at the same time

Exclusion Criteria:

1. Age under 18 years or upper 60
2. Pregnant woman or lactation
3. Incapability to give consent
4. No written informed consent