GI issues due to Bi-Pap usage

Ever since I started using a Bi-Pap machine I have had issues with bloating, non-stop belching and also heartburn and acid reflux. My Dr has adjusted the pressure twice already but the issues still remain. Pepto bismol helps a little. The bloating along with pain is worse after eating. Is there anyone else that has the same issues and can you recommend any treatment that works for you. Thank you