Psychic_Defective wrote:
It might be anger directed towards the feeling of helplessness that an operation gives you.
You're out cold on a slab, unable to defend yourself while someone you barely know is digging around inside you.
It leaves some people feeling violated.
The good thing is that if you realize that's the cause (IF that actually is the cause) you'll be able to come to terms with it that much easier.
Actually, that may be very true; quite often the patient has mixed feelings towards the surgeons at the end of an operation. On the one hand, they feel they should be grateful and shake their hand, but on the other, they subconsciously want revenge against the people who were hurting them!
Did the operation go smoothly or did you feel something wasn't correct in the way it was handled? (before- and aftercare as well). I'm not suggesting you start looking around for things to sue, but as Psychic_Defective said, if you find the reason why you're angry, it will make it easier to cope. It's probably not a direct effect of the anaesthetic, although it's common to feel fatigued for a long time afterwards.
You may also be able to get post-operative counselling somewhere; I'm sure it's not unheard of.