Bile Reflux after Whipple

Hello. I had Whipple surgery for pancreatic cancer in June of 2020 and as of April 2022 I started getting severe bile reflux. My gastro doctor just put me on Cholestyramine which I've been on for about 5 days now but I don't see much of an improvement. I was just wondering if anybody has any ideas or things that have worked for you. Thank you.