Mostly it's just treating the symptoms because the gastroenterologist just says everything is "healthy". What symptoms are you having specifically?

Reducing dairy helped for me. I switched to almond or oat milk wherever possible and when I can't, I keep lactaid on hand including in my purse.

I also take a stool softener once a week and stay hydrated to make sure I stay regular. I take Adderall for the ADHD side of the AuDHD, so hydration is always difficult because then I pee a lot. But the Adderall means I dont need as much coffee, which is an irritant for me.

For the reflux that didn't get resolved by reducing dairy and coffee, I make sure not to eat or drink anything, including water, near bedtime and if I still have some feeling like it's going to come up I take supplements with alginic acid recommend by my vocal therapist. And I take pantoprazole prescribed by my gastro.