What kind of surgery was it? Some surgeries are tougher on iguanas than others.
Is this a fully grown iguana, past 3 1/2 years old?
Eating sheds is fairly common, and is not dangerous.
But not having water for that long is dangerous. Normally she gets a lot of her needed water in her food. Now she has no source for it. Did you see the description of the drip-bowl in the posts just below? Your ig might respond to it, because in the wild they are predisposed to drink water that is flowing down tree trunks and branches during a rain. For the first time, this ig might drink from a bowl of "moving" water.
You might end up needing to syringe water to her by mouth. I can explain that if you wish.
As long as she gets water, about 6 cc/day or more in 3cc doses, her refusal to eat food is not yet a serious problem. 3cc plastic syringes are cheap at pharmacies.
But if she goes beyond six weeks without eating voluntarily, you will need to syringe food to her as well as water. Once you and the iguana learn how to do it and what's going on, it becomes fairly easy.
I syringe-fed food and water to a large adult female after removal of badly infected ovaries, for six months before she miraculously suddenly started eating off her plate. I had given her plates of good mixed food all those months, and it ended in success.
BTW, almost all iguanas pick up and/or eat non-food items like coins, peach pits, dirt from potted plants (I think this one might sometimes be related to the need for minerals, as in salt and clay licks in the wild), and worst of all, any kind of string or thread. There is even a case of an ig eating his owner's panties and passing them all the way to his vent, where the owner helped pull them out.
If you want, I can describe how to syringe a balanced diet to her. The method is not what you would think.