At hospital romoved 2 year old tonsils low fever before surgery now has fever 101 same day as surgery wont drink any thing on IV fluids. Opinion?

Talk to surgeon. Children are miserable after tonsil surgery. Initially they are fine, enjoying ice cream and so forth. Then the throat becomes very painful. The surgeon will prescribe lots of things to try and help, but ensuring the child stays hydrated is most important. The larger the child, the more resistant. The IV is not unusual if they won't drink. Talk to surgeon about issues.
See below. Likely related to the surgery itself. Fevers are common after surgery. Since the child can't drink anything, it is good that IV is being used. If concerned, call the ENT for advise.