Well, what I CAN tell you is that it is normal psychological development for him to be going through at this point. My babe is 15 months and is already beginning. So I recently re-read some more info about what to expect and what's going on for them at this age. The encouragement I can offer to you is that if he hadn't gone through this now, his teenage rebellion would be even worse. And that it is important HOW you move through this. You need as much emotional support as possible so that you can remain centered and calm. You definitely need to have or create a safe place for him to carry on, then you have to walk away. The more you try to calm him down and help him in that moment, the worse it becomes and the longer this stage will prolong. Even if he's screaming and crying at the top of his lungs, you calmly say "this is not okay, I know you're upset but you cannot talk to mommy this way. Mommy cannot help you when you're like this. I am going to walk away and when you calm down I will be back." Then let him carry on as he needs to (in his crib, playpen, etc), do your best not to rush in no matter how much louder he gets and WAIT. Promise you that he'll calm down sooner that way and that he will get through this phase quicker. THEN, you walk back in and pretty much say the same thing "mommy is sorry you were upset, I am so glad that you were able to calm down because mommy cannot help you when you are like this. But I love you and I'm glad you're feeling better." then hug and kiss him. And definitely make sure you give him tons of hugs/kisses and positive reinforcement throughout the day when he is behaving positively (i.e. "yae, we got to read a book together [smooch smooch], "what a smart boy, you knew where the ball was! [smooch smooch]).
It's a tough time that we are going to have to get through, but just remember that the light at the end of the tunnel will come and if we can maximize the psychological benefits of it then we'll all be the better for it in the long run. The underlying reason for all this, by the way, is that they are moving towards independence. That 'move' is scary for them b/c at the same time they recognize their dependence. The ambivalence is SO strong that it's frustrating and overwhelming for them. As much as possible, they need to feel respected. Yet obviously, we have to keep them safe and not teach them that they can have their way whenever they want. The doctor should especially know this and should've (don't know if he did) started by checking a doll's ears, then yours, then explaining what he was going to do and asking if it was okay. Even IF your son would've still freaked, at the core of it there wouldn't be as much of an insult to his sense of himself and his body.
Anyway, hope this helps and know that you are not alone.
-N.