Hey there Leah - First off, good deal on getting to the doctor's quickly. Have you seen a specialist? Sorry for my ignorance, I'm unfamiliar with your case for the most part. I believe you mentioned something about a specialist in the past, but specifics escape me at the moment. ER docs generally are not gastro docs, that's mainly why the question.
Second, once you get a "diagnosis" for this issue, make sure to get a second opinion, both on the diagnosis and the prognosis. Some docs are very very quick to send you under the knife in certain cases. I'm not saying this is one of them, not at all, but I am saying that if you get a "surgery-happy" doc, make sure to go to another gastro in the area and confirm his findings and plan of "fixing it".
Lastly - don't get too worked up about this. I realize this is scary territory so to speak, but trust me, in the 20 years that I've been dealing with this, all that getting scared about things has done is to make them potentially worse. Hit me up on AIM sometime. I saw you messaged me the other day, but you didn't answer my reply
*sniffle*
Hang in there!