Suggest Treatment For Chronic Mid And Lower Stomach Pain

I have had "benign" sometimes bothersome arrhythmias since the early 90's. I take a bb to keep th episodes down to a minimum. I have been having chronic severe mid and lower left stomach pains, especially upon awakening in the morning. Despite using PPi's and H2blockers as well as, an endoscopy and camera capsule study recently. Today I was pressing on my lower stomach while having this pain and noticed it triggered PVC's and a elevated or somewhat rapid heart beat while palpaltating areas of my lower abdomin?? Do you have any suggestions what cvan be causing the pain if it's NOT always food and rarely GERD and what other testing I could do. I wonder if I have hormone secreting tumors somwhere near the GI tract or OUTSIDE the GI tract something affecting vagas nerve itself? Would an Ultasound of the abdomin be a wasted test and I should go right to an MRI or CT of entire abdomin, including the pancreas and gallbladder??