Lax lower esophageal sphincter can be a cause of acid reflux
Bile reflux is very unlikely unless there is some stomach operation
You can confirm acid reflux by 24hrs pH metry if its there then there are some endoscopic procedure like ARMA( ANTI REFLUX MUCOSAL ABLATION) which can help you
Next Steps
kindly search of any gastroenterologist who specialises in GI Motility disorders near you he can help you
Health Tips
I also specialise in GI Motility
we can connect online