I am not an attorney but have a background in ADA. If your job description states that regular attendance is an essential function AND it correlates with business need, you may not have too much of a case. I would really advise you to seek legal advice to see where you stand with this. If you were doing a job where you could be gone and it wouldn't matter as far as the business operating I think you will have a better chance. Also, does your company allow any leave time beyond FMLA? Maybe they could have offered you a LOA as a resonable accommodation. Again, I would definatly seek legal advice. Good luck to you, I know how hard it is to keep working with this disease, especially if it is not well controlled.