Hi I don't think I have to say to avoid drinking alcohol,drugs or using tobacco, because it appears that on some level it is already known. Alcohol is bad for the stomach and bowel system as are other non-food substances that don't grow on trees, plants or bushes.
Sweets are said to cause panic attacks.
I would not use cheese, yogurt or bacteria cultured bread to avoid the gas that may be a factor in the burping.
I would follow other good healthy lifestyle tips also such as a daily walk in sunshine and fresh air (except between 10 a.m. and 2 p.m.), plenty of good water a fruit, grain, vegetable, nut diet. Some foods such as potatoes, homemade bread, apples, toast, and rice are supposed to be good to stop diarrhea.
Since an endoscopy has already been done I am not sure it is a celiac gluten problem and even if it was some people on the gluten free diet have more trouble with other things later so I am not sure I would try that just yet.
Peace, If desired let me know how it goes.