Hi.
Thanks for your query.
Noted the history of you being suffering from Gastric trouble, gases, and IBS for many years and no relief in spite of trying the medications and change in diet and so on .
I would advise you the following:
Consult a Gastroenterologist for proper clinical evaluation.
Make a list of the foods and beverages that cause the problems and stop them altogether.
Make a list of the foods and beverages that suit your abdomen and continue those only, never try something new as it can have more problems.
Go for investigations of blood, urine and stool,
Colonoscopy, upper GI
Endoscopy and CT scan of the abdomen.
If there is a problem get treated as per the causes found.
IF all the investigations are normal then take treatment on the basis of IBS, that is
irritable bowel syndrome.
It is very necessary to have control over
anxiety and/or stress as these can be the major causative factors.