You have not mentioned about any upper GI
endoscopy which I am sure must have also been done. What were the findings.It appears you have acid reflux- disease in all probability. Take Pantaprazole 20 mg along with semithicone on empty stomach twice a day and after meals try to lie in reclined posture ( Head side and chest in higher position then the abdomen and lower body so that gravity acts to keep the food passage downwards) Also since
gall bladder is removed, take digestive enymes post meals and avoid fats in diet