in spite of this the oesophagus function tests used to evaluate the gastro-oesophageal region -- basal gastro-oesophageal sphincter pressure , acid perfusion test , acid clearing test , and intensity of acid gastro-oesophageal reflux measured by automatic integration of the ph variations as a function of time in arbitrarily chosen ph intervals during 12 h together with peristaltic activity in the oesophagus -- were unchanged .
C0017168
acid
C0014876
oesophagus