Was your Whipple procedure "pylorus-preserving"? Mine was, and I did not have stomach spasm issues afterward.

However, after my tumor recurrence, gastric outlet obstruction and stent insertion, it became like a pylorus-NON-preserving Whipple -- essentially an open pipe out the bottom of my stomach.

After the stent is when my stomach started having spasms. I get some relief from taking Bentyl (dicyclomine).

Maybe not relevant, but an angle to consider.