Gamca record duration

There is no GAMCA Bahrain.

GAMCA is present outside of GCC to screen workers coming to the GCC. 

GAMCA usually allows you to retest after 6 months depending on the reason you were unfit for.  If it's something like HIV, Hepatitis etc then no hope or chance for a retest.

If you get retested and are marked FIT, they will automatically update their systems and when Bahrain LMRA looks in their system at GAMCA record, it will appear as FIT.

On the other hand, if you were tested INSIDE Bahrain after coming here and were marked UNFIT and deported/denied visas as a result, then you are out of luck.  That record will be part of LMRA/Immigration forever.