Most kids have to be poked multiple times.I would agree - get a second opinion. It would be a shame to give up on Remicade, which is the a very effective treatment for fistulas just for bad veins.
It's not ideal but they can even place IVs in the feet if they can't find veins in the arms.
There are VERY few IBD meds, especially for a kiddo with severe IBD, so you don't want to run through them too quickly.
Humira shouldn't be given every 3 weeks. The only time I've ever heard of that is if the child is in remission and has been stable for months to years. Then they sometimes try to lower the dose.
For a kid who is not remission and has a fistula that won't heal, that is not the standard treatment.
The levels don't really matter as much if they're too high - as long as his WBC is ok. If they're too low, that's when it's a problem.
We have been all the way up 4x the normal dose for Remicade. I'm sure my daughter's levels were very high at that point but that was not a concern for the doctors. The point was to get her into remission.