Suggest Treatment For Gastritis

Following an endoscopy 18 months ago, I was diagnosed Gastritis. I was prescribed Omeprazole to take as and when required, not on a regular basis. Between then and approx 4 weeks ago, I have had 3 or 4 attacks of Gastritis symptons, which after 24 hours and medication, cleared up. For the last 4 weeks I have suffered continually with one or more of the following symptons: abdominal pain, nausea, vomiting (once), shivers, tiredness particularly with the eyes, pain in my sides and going up the back to the shoulder blades, lower abdominal pain and bloating, excessive flatulence, feelings of possible bowel movement. On two occasions I had to visit an out of hours doctor, followed by 2 visits to my GP. I am having bood tests done and being referred for an ultrasound scan to check for gallstones. I am worried that this is something more than gastritis and would welcome any advice. For your information, I suffer from social anxiety disorder and the last 6 or so weeks has been a very anxious time including starting a new job. Many thanks.