Has anyone's LO dealt with delayed gastric emptying or been diagnosed with Gastroparesis?

My 10.5 month old twins have had ongoing issues with solid foods - mostly major sleep problems after eating solids. Their regular ped suggested that they might be silent refluxing so we put them back on Zantac (they both took reflux meds when they were younger but had outgrown the spit up, back arching, etc.). Zantac has been helping a lot on days that they only have breastmilk and formula (Alice slept through the night last night!) but after solids they wake up 5-7 times (EACH!) and stay up screaming for 45 min-2 hrs some times.

Anyway, because of the sleep issues we are all a little gun shy of going full steam with solids. Today we had a GI appt and he does not believe the solids are causing reflux issues. Apparently it's not very common to have reflux of liquids controlled, but solids cause an issue because solids are literally more solid and harder to reflux. There's no rhyme or reason to what solids are causing the issues (seems to be dependent on qty) so he doesn't think it's allergies. He suggested that we may be dealing with delayed gastric emptying. Testing would require barium which he does not recommend before age one, so we are going to reevaluate after their first birthday. In the meantime, we are going to stick with formula and breastmilk only. I feel really relieved about this because I've been feeling guilty every day that I didn't give them solids even though those days they were much more comfortable and we all slept better! I just hope they eventually can handle solid foods, though!

Has anyone else dealt with this? Did you go through testing? Did your LO eventually outgrow it or did you have to go through some other course of treatment? Thanks!