Hi,
As I said in the previous post I don't know if the pest strips could be the cause.
I would however take them ( or the packet ) to the vet so he can look at the active ingredients and describe exactly how you used them. If you left her waterbowl in for example then that is a horrendously bad thing as most of these poisons are water soluable.
Did you ask the vet about intervening surgically ( ie with a big needle ) to try and release some of the gas?
dr del