Background: Water-perfused conventional esophageal manometry has been the investigative tool of choice for evaluating esophageal motility disorders. Many studies demonstrated that many factors including difference in population group can affect the result of the manometric test.

Objective: To establish normal values of water-perfused conventional manometry for Thai people.

Material and Method: Thirty healthy volunteers (15 of each sex, aged 19 to 53 years) were recruited. Esophageal manometry using the water-perfused system was performed in each volunteer with ten 5-mL of water swallow and stationary pull-through technique in supine position. The values were calculated and demonstrated in mean, median, and 5^th to 95^th percentile. The effects of the gender on the measured parameters were analyzed.

Results: The mean value of peak contraction pressure and contraction time of the distal esophagus were 107.6 mmHg (5^th to 95^th percentile: 50.6 to 158.9 mmHg) and 3.3 s (2.63 to 4.59 s). The propagation velocity was 46.2 mm/s. The mean resting pressure of the lower esophageal sphincter was 6.12 mmHg. (5^th to 95^th percentile: 3.9 to 7.9 mmHg). These key parameters were not considerable different from those reported from the Western studies. The values were similar between genders except mean resting pressure and relaxation time of the LES, which were significantly higher in the female group.

Conclusion: A set of normal values for water-perfused esophageal manometry using stationary pull-through technique was established. Because the size of the population recruited was relatively small, further studies may be required to validate our results.

Keywords: Water-perfused, Esophageal manometry, Manometric test, Pull-through technique, Thai