Clarification on my IBS symptoms. Taste.

Hi, I am having stomach problems in past 1.5 years. 3 months before I had stomach pain whenever I had allergy food like milk and spicy. But in last 2 months i am having moderate to severe stomach burning without  pain but with vomiting sensation sometimes and mouth bitter taste in all burning times.i Have done endoscopy and the report came normal even biopsy. Doctor told it looks like IBS. Whenever I am having stomach burning, i am urinating abnormally with full clear flow and without any pain and irritation. I have done urine culture test and that too came normal without any infection.attaching my endoscopy report FYR. Iam facing this recurrently in last 2 months.Kindly suggest IBS causing this stomach burning sensation and more urination with mouth bitter taste. Regards, Ramya