Hi, Carol!
I looked at my normal lab values chart that I have for rounds, and either the doc's using some random scale or those are values from a different test . . . ? Plus, there is no value above a 14 on the pH scale, as 14 is the value for a solution of only strong base with absolutely no acid, so a value of 21 is impossible (unless he multiplied the pH by 10 to give you a whole number instead of a decimal, which is possible). That being said, he might have been measuring the volume of acid in the stomach, which may be a more likely scenario with the numbers you gave. The pH probe should have measured from a 3 to a 6, normally.
I wish I could tell you more, but I'm still a baby in the medical field.
