Of course we should always do what the doctor tells us, because we all know that Doctors NEVER make any kinds of mistakes whatsoever. They are perfect beings put here to keep us on the perfect path. Bah!
As a side note, my family doctor once prescribed an anti-depressant for my spouse. She called BS on the diagnosis, did her own research online (which is not normally a good thing. I know, I know...) and took the results back to him. He actually agreed with her, changed her meds and all is well and we think better of him as a doctor not because he screwed up, but because he listened.