Is the gas expelled by belching?
He said the more he ate, the more he farted.
He has passed more gas than usual within the last two days.
Be careful not to fart in the public.
I have an upset stomach.
He has bouts of diarrhea.=He is having trouble with diarrhea.
He has persistent constipation.
Something has upset my stomach for two weeks.
Do you have regular bowel movement?