Herbal supplements have helped me immensely: chia and flax seeds along with aloe Vera, slippery elm and marshmallow root powder particularly. These are often taken as supplements these days (not sure you would consider them as alternatives anymore) and are way more effective in calming down gerd and ibs in the long term. PPIs such as nexium are really effective often in the short-term (specifically for burning sensations with ibs) but will probably cause complications in the long run.

Meditation and yoga definitely helps and there are credible scientific articles on apps such as nerva which incorporates gut hypnotherapy and can be as effective as the low FODMAP diet. Often ibs has visceral hypersensitivity (nerves being too sensitive) associated with it. That is why such alternatives often can work really well. At the end of the day, I think a combination of all these help the most.