Last week, I saw the doctor Janzen. I described my problem, and he gave me a piece of paper. There are four letter, G.E.R.D. He said I may have this. And at the same time, he gave me two bottles of pills. One pill each day, for two weeks. He said if I get back normal in two weeks, that means it is.
Now, today morning, I took the first pill and the whole day is good.
I checked Wikipedia, it said:
Gastroesophageal reflux disease (GERD), gastro-oesophageal reflux disease (GORD), gastric reflux disease, or acid reflux disease is a chronic symptom of mucosal damage caused by stomach acid coming up from the stomach into the esophagus.