
Susan
I'm so sorry you're having to watch your little guy go through this.

Barb is right on, I think. Pain, especially so soon after surgery, is a major problem, and it's very possible his shunt isn't working as it should, especially if his behavior is very different from his usual, and most especially if it's worsening since surgery. Check his incisions carefully for any swelling or redness, and note any fever or other symptoms you can see (e.g. change in gait, anything that may be even minor seizure activity).
Barb is right about insisting that they take your concerns seriously, too. Stay as long as you have to, and refuse to leave until they go over him with a fine-tooth comb to rule out
any possible problems. (I don't know how else to say this, but if his father is involved in his life to any degree, have him stand up for you both, too. Doctors are much more likely to listen to men than to us.

)
Good luck, and please keep us up to date.
LIZARD