Why is my 9 year old waking up with terrible nausea after gallbladder removal?

[ginabgilmore]

My son had his gallbladder removed in January 2017 after 4 months of gallbladder attacks finally getting diagnosed with a HIDA scan of 0%.  He has done great for 8 months.  He had a couple of times of temporary stomach upset from fatty foods like ice cream.  He now wakes up every morning feeling like he needs to vomit running to the toilet.  He never vomits but coughs and welches like he is about to.  All tests come back negative.  We have done scope, ultrasound, MRCP, stomach emptying test, rounds of blood work.  We saw a different pediatric GI to see if he needs ERCP and he did not think he needs it.  His liver enzymes are normal and so are all the X-rays.

We have tried protonix, balcofen muscle relaxer, propranolol, Donnatal with no results.  We have also seen a neurologist and treated for abdominal migraines but no improvement.  He has these episodes where he gets flushed, ears get hot, BP and pulse are elevated to 130/88 and pulse can be 108.  Cardiologist said his heart is fine with an EKG and heart ultrasound.  These are the times where the stomach squeezing and nausea are worse.  It seems to be happening worse when his stomach is empty.

This last Pediatric GI is referring us to a functional abdominal pain clinic.  We have also tried doxycycline with no results.  I do not think it is IBS.  Also he has gained 18 pounds in the last 3 months which is very concerning especially on a 9 year old.  I am worried this will lead to diabetes.  

Please help with any info since no doctors are helping.