Five days ago, I went to the ER with severe nausea, fatigue, weakness and dyspepsia, along with right side abdominal pain which I felt predominantly under my right rib (sometimes radiating to my back). I'd been experiencing those symptoms for about 4 days. I developed a non-painful 'sensation'/fullness under my right rib a week before that, but had no other symptoms. So, it took about 2 weeks total before I hit the ER. Ultrasound of my gallbladder was normal. Blood test results were all normal. U/A = normal. I then had a CT scan of my right abdomen, and it also came back normal. Also relevant, I was dx with IBS (constipating) at age 16 (I'm 35 now). FYI - bowel movements did not relieve any of these symptoms. I am very fit, exercise daily, avoid preservatives and eat a mostly vegetarian gluten-, dairy- and soy-free diet, and am normal weight and non-diabetic. Doctor sent me home with scripts for dicyclomine, reglan and nexium and said I could have gastritis, an ulcer or a low-functioning gallbladder.
Since I've come home, my indigestion symptoms have worsened. I didn't find any of the drugs to be particularly helpful. For the first 2 days, I felt my abdomen was full of gas, and I was having uncontrollable anxiety and heart palpitations (overactive nervous system response to gut inflammation?). I cut beans out of my diet to reduce gassiness and the heart palpitations subsided. I even managed to exercise twice this week; however, the nausea persists, as does the right-side abdominal discomfort which is sometimes felt under my right rib, sometimes in my back rib area, and sometimes in my right flank. Today I developed terrible burning at the base of my sternum. If I let my stomach get completely empty, the burning is worse and it is sometimes (but not always) relieved a little bit by eating.
I probably need to see a gastroenterologist, but I don't have insurance so I'm trying to self-treat to avoid incurring any additional debt. Based on these symptoms, does it sound like gastritis or an ulcer, or something else? If I were to go to a gastroenterologist, what tests would s/he likely need to run in order to determine the source of the problem, and how expensive would those tests be?