Same experience here. Adults flat lied to me about it -- in the first place they didn't even tell me I was going in to get my tonsils out. They told me I was going to visit someone in the hospital. Then when we got there this big crabby nurse the size of a tank grabbed me and carted me away. And it DID hurt, and I couldn't swallow that ice cream either, and the anesthetic made me sick as a dog. I gagged and wretched and caused the incision to open up and bleed all over the place. I was afraid I was going to drown in my own blood and it scared me within an inch of my life. The whole thing was traumatic. The memory of all that is as clear as the day it happened.
That was the only surgery I had ever had before my hips (60-some years later), and I think it was that experience that made me so blindly terrified of the hip surgery. The hips were a walk in the park compared to that tonsils mess.
I think it is absolutely inexcusable to lie to a child about something like that ("visiting, etc."). Part of me is angry to this day about that, and I lost a bit of trust for my parents that day.