Unfortunately many addicts have underlying mental health issues and self-medicate.
I certainly was one of them.
I had horrid reflux for years after I got clean/sober, and it got so bad that I had to have an endoscopy as I was having trouble keeping anything down.
It turned out the opening out of my stomach was scarred so badly they couldn't get the scope through it.
That problem started brewing long ago when I was still using. Crystal meth was my drug of choice, and I'd literally go days on end without eating.
I had major surgery almost 3 years ago and have not had any reflux since.
I am very blessed I didn't end up with more damage than I had when I got clean/sober.