Need to some advice urgently!

3.5 year old son has suffered from severe reflux since birth, since then we discovered he is allergic to dairy, eggs, nuts and others. It is possible the dairy allergy may have caused the reflux, some Dr's think so some dont.
Anyway after 3 scopes under GA and biopsies we have seen that the burns that he had right up to his vocal cords have healed (possible from all the reflux medication helping or maybe the removal or dairy or both).

Anyway biopsy shows gastro inflimation and signs of ceoliacs. Further blood tests (x 2) show Ceoliacs as well. This is not being addressed util another set of BT's in 5 months. If has not changed nothing will be done. No idea what will happen if has changed.

BIG PROBLEM IS: long term iron defficiency. He is now meant to be on 7ml of ferro liquid a day but he wont take it. I have tried mixing in juice (he does not drink juice), jelly, chockie,coke anything its just tha strong he gags and throws it up. We have tried crushing half a tab of gradumet but he does not eat enough food for me to hid it in sucessfully. Now he wont even take panadol, he thinks I am trying to poison him I am sure.

He is not sleeping well and his diet is getting worse, he just wont eat. Its a miracle he is still growing.

How can I get his iron up if he wont eat or take the medicine?
This is killing me, he wont let me help him and I am loosing my patience!

HELP!!!!!!!!!!!