What Causes Recurring Burning Sensation In Stomach?

My mom has been suffering from burning in her stomach we took her to ER on Thursday they gave her morphine for pain they did a CT scan with contrast and said they couldn t see any problems they kept her at the hospital for 2 days to receive the pain I brought her home yesterday and today her stomach burns like it did last Thursday when I took her to ER. Does this sound like an ulcer to you ?