Esophageal manometric studies, 24-hrs esophageal pH monitoring, and measurement of serum gastrin concentration were carried out in fourteen cases with congenital hypertrophic pyloric stenosis to investigate the esophago-cardiac function before and after operation. The results were as follows: 1. Manometric studies; The tone of high pressure zone (HPZ) at the distal esophagus before operation was significantly lower than that after operation, (78±52.5 versus 111±38.0 mmH_2O. p<0.01). There was no difference in the length of HPZ before and after operation. The end expiratory pressure in the esophagus before operation was higher than that in the stomach, whereas after operation, the esophageal pressure was lower than the gastric pressure. 2. 24-hrs pH monitoring of the distal esophagus; The percent time of pH<4 for the total period (24 hrs) before operation was 12.5±4.74% and that after operation was 0.95±0.96%. The difference was statistically significant. The number of reflux episodes before operation was significantly more than that after operation. (123±60 times versus 18±18, p<0.05). 3. The serum gastrin concentration; The mean of serum gastrin concentration before operation was 60.4±23.6 pg/ml, whereas after operation, that was 122.4±60.4 pg/ml. the difference was statistically significant (p<0.05). But, there was no statistical correlation between the tone of HPZ and the serum gastrin concentration. These results indicate that the esophago-cardiac function of congenital hypertrophic pyloric stenosis before operation is impaired.
