Hi.
Thanks for your query.
Noted the history of constant pain in upper and lower left region,
heartburn no matter what you take, vomit yellow acid, lost 10 pounds, have been to a Doctor, ran CT scan which was normal, suggested GI Doctor, wants to know whether this could be an ulcer...
Heartburn means you have a problem of GERD, that is
gastroesophageal reflux disease. In such a case you need an Upper GI Endoscopy. It will conform about the gastritis or ulcer,
esophagitis, lax lower esophageal sphincter and so on.
Pain in the upper and lower left region of the stomach can be due to colitis and since CT scan is normal go for
colonoscopy and biopsy, tests of stool, blood and urine. Get treated as colitis and as per the reports.
If all the reports are normal, then get treated as IBS that is
irritable bowel syndrome.