Do you have a SSDI atty?
The surgeon should be able to write a strong letter to the judge or case worker etc, advising of the urgency of the gallbladder treatment/surgery.

I would hope that an official letter from the surgeon will be proof enough for a postponement of the SSDI case & tests.

Maybe the person that said "there is no getting out of it" doesn't understand what happened or does not believe the story? Proof is needed.

An offical letter from the surgeon should do it.