Assuming you live in the U. S......

i am pretty sure bipolar disorder is covered by the ADA (americans with disabilities act) .... and work is not supposed to be allowed to reprimand you if you have a medical reason for your absense... plus there is also the FMLA (family medical leave act) which i think bipolar is covered by also. and another great resource is the EEOC (equal employment opportunity commission), to file a discrimination complaint.

i was on FMLA for a non-specified diagnosis last year for three months... doctor just signed my papers, they didnt even need to know the DX.