hi, you can start by eliminating all sweets from his diet for one week.
Get your baby in to see a good pediatric gastroenterologist, and let him guide you from there.. Did the doctor only do an upper scope of his stomach? He needs one of his bowel. I would also see an endocrinologist. Why has your pediatrician allowed this to continue? Does he eat enough? Is he developing at the correct speed for his age? I would seek out a second pediatrician also for help, I think your current who is failing you and your son. Cincinnati Childrens Hospital located in Cincinnati Ohio has the best pediatric unit in the country for gastroenterology. If you could take him there, they can and will help him. They can also arrange a place for you to stay with him. This is what I would do. People travel from all over the country to get help at this hospital when having no help, or answers with their child. I can get you all the information if you are interested.