Ok, I have this little baby boy who is hard to burp and at night it is worse. Not only this, at night, he has one ounce and you can definitely hear the gulping sounds he makes in addition to the gas or liquid hitting his stomach and this causes him to need burping at every ounce. He's strictly on Playtex bottles after using a few other types. Now I am wondering if it's the Playtex brand that is causing the above. What type of bottle do you use?