I myself had my gallbladder removed about 4 years ago and thought that we be the end to all my stomach problems, but I like you have had SEVERE upper abdominal pain with the pain radiating to my back. For me the pain didn’t come until about a year afterward so it could not be related but I sure described it the same way you did, I don’t remember that feeling at all. Mine only comes on about every 2 months or and cannot think of anything that I could be eating to cause this. One time I had to go to the ER I really thought something bad was happening but they found nothing at all. So I have given up I figure if something really bad happens off to the the ER I will go.I hope your pain is just from healing, good luck