Gas is not produced in the stomach! - It is the swallowed air that gets trapped in the stomach, causes belching
- changing the eating pattern will help
But it could be produced lower down, in the intestine - causes farting.
You could be having gastritis
or IBS (Irritable Bowel Syndrome
) / at times infection of infestation.
Stool analysis / endoscopy
(upper and lower) - can elucidate diagnosis
A gastro-enterologist is the proper person for assessment and assistance
Wish you a speedy recovery