Jessica,I had the same expereince with that kind of pain in that same area and they said the same thing to me: constipation. And I agreed I was constipated because I was but I've been constipated before and THAT pain was NOT the same kind of pain I was feeling and I told them that in the hospital and the ER. The doctor said as he discharged me that he was not 100% sure why I had the constipation or why I had the 103.5 degree temperature. The findings on the outside of the stomach concluded that there was no significant leakage (dangereous situation because it could make you septic and people die from that condition) but I asked him maybe they should look on the inside of my esophogus to just double check that everything was all right and he declined because he said there was no leakage.
But the pain returned less than two months later and this time after all the regular tests repeating everything all over again and not finding anything additional (constipation again was present) they finally checked and looked down my throat and esophagus and stomach. The band had caused a hole in my stomach and I tell you when you describe your pain I felt just like you did. The pain was the most excrusianting I have ever felt in my entire life....