What are remedies for gall bladder stone?

My dad has gall bladder stone, biggest having size of 18mm with some small stones. What are our options? We are seeing doctor and hr recommended surgery. Please provide useful suggestions on can it be treated without one?
Don't say trash like you should see a doctor or seek doctor's help, please don't be morons.
Updates
+1 y
I need other alternatives, stop with surgery. I already know that.
What are remedies for gall bladder stone?
Post Opinion