I don't know if there is a difference for you flying guys, but I did the "fatigue tour" to the doc after they changed the shift pattern at the OCC.
You'll get the usual interview where you tell him all the symptoms you have.
After giving me the sick certificate for fatigue, the doc referred me to the American Hospital for check up with a specialist.
Got a nice sleeping monitor that almost strangled me at night
Anyway, I called certified sick due to fatigue for every single early shift in that month.
but stopped that after Al Retard changed the pattern back.
I dont know if that caused the change of his mind but I would highly suggest for you pilots to do a similar approach
Needless to say I put in my resignation, also because of that kind of crap. But the impotent rage of AAR, cause he couldn't do anything against a fatigued employee backed by the docs, was priceless!!
P.S hope the docs still have the balls to back you up.