I have a knot at the top of my abdomine right under my rib cage that comes and goes. (Probably for the last 8 months) It does hurt when I can feel it there, the scary thing is it pulsates like a heart beat! It feels hard to touch, it's not gas that moves around easily. I have had symptoms for IBS in the past, but this seems non related. It's not in my lower stomach or intestional area. It doesn't give me a feeling of indigestion of heartburn. From what I can tell stress can be a trigger. Could it be a ulcer? I don't have insurance right now, can't afford to go run a billion tests that may not give me answers. But will go if needed. Please try to give me an idea of what the possibilities are here.