I'm 32 years old and had a tonsillectomy/adnoidectomy on February 5. I have no comparison to what kids go through, but this seems pretty painful. The first day, I got sick from the anesthia. My recommendation would be to wait about 5 hours after you get home from surgery before trying to eat. (When I got home, I was quite hungry and had an Ensure, which I vomited up right away...eww.)
What others have said here I have found true: the pain is inconsistent and I'm unable to foresee it. One minute, I feel almost normal again and then I reel backwards and have excruciating pain again. Last night, I became pretty constipated (sorry for TMI, but it's important!) Apparently, this is common with the lack of movement/activity combined with the drugs for pain. So be sure to eat fiber (think oatmeal!) when possible along with all that water we're supposed to drink.
I had an issue two nights ago where one part of my right tonsil suddenly formed what looked like a giant (larger than a pencil eraser) blood blister. After checking with the doctor, there was no need for alarm. Normal part of healing, I guess, so don't worry if you see the same/similar. It's only when the blood is running (like a bloody nose) that you should worry.
Today is day 6 post-op for me, and I tried to only take tylenol today to no avail...back to vicodin for me. But the good news is that I think the scabs are getting smaller. I see more pinkish areas appearing, even though there is quite a bit of white gunk left.
Foods that seem to be okay for me to eat are oatmeal, scrambled eggs, cream of wheat, sherbet, popsicles, cup noodles, and milk. I also had some sweet tea which was lovely on the throat...highly recommended! Just be sure to NOT add lemon.
Hope that this information is helpful for somebody out there. I know I did a lot of research before my surgery date and reading the testimonials helped prepare me.