I think I've said before, GERD doesn't play fair! When I first got it I looked into the causes identified in the studies, for acid reflux and gastritis (I have both). According to the studies I should be overweight, or bit heavy on the drink, or have a poor diet with lots of fast food, drink buckets of coke or coffee, or, failing all that, I must have Helicobacter. Nope. I have none of the above and never have. And although I have a hernia, it's tiny and wasn't even present on my first scope, thus ruling that out as the cause.
You can drive yourself crazy wanting to know the cause. I'd settle for anything that just makes it more liveable.
And it's the same for other diseases: my mother never smoked, never used hormonal treatments and breastfed all her babies, yet she still managed to die of breast cancer...... "There are more things in heaven and earth ...."
New stuff: GERD, Recurrent cystitis/Overactive bladder
Lifelong stuff: Food allergies/intolerance, eczema, asthma