@johntw Replying to my own comment as a follow up so read that one first for context.

Following up on my post from 2 months ago, I've actually had some pain and heartburn show up since then. I went to see a new GI specialist last week who seems more attentive than the first, but he also basically laughed in my face when I asked if an EGD could somehow "activate" a previously asymptomatic hiatal hernia.

Just like my first GI doc, he was also very dismissive of the hiatal hernia idea in general and said the issue is likely slow gastric emptying aka gastroparesis. Abdominal CT done since my last post was unremarkable. New GI doc ordered an ultrasound and a gastric emptying test so I should be doing those next week. I'll report back after I get results and see him again in a couple weeks.