[24-hour esophageal pH monitoring. An analysis of 21 cases].

Esophageal pH monitoring was carried out with self-made portable pH recorder in 21 subjects for 24 hours under normal conditions. The results were as follows: the number of physiological gastroesophageal reflux (GER, pH < 4) was less than 23 times; the percentage of GER duration calculated by dividing the cumulative time of pH less than 4 by the total monitoring time was less than 1.4; the percentage was about 2 in upright position and less than 0.2 in lying position; the duration of the longest reflux episode was less than 5 minutes; the physiological gastroesophageal reflux occurred more often in upright position; while the pathological GER took place both in upright and lying position. Our study also indicated that the degree of esophagitis had no relation with the type of GER.