These 2 To 3 Weeks , The Gas Always Choke

These 2 to 3 weeks , the gas always choke at the throat, after eating with rice or drink with water (especially at nite 3 to 4 hrs before sleep)
I do not feel there is a burning sensation around my chest or throat areas n I'm only feel upper left chest is mild pain n upper back(mild numb)and I have went through CT scan, they have found nothing wrong with my heart
May I ask u, what will be causes n is it serious n what actions can be taken?
Thks