Doesn't ADA cover this?

I have a disability that is covered under the ADA laws. Suddenly my employer wants me to go on intermittant FMLA to "protect" me. I do not abuse any leave time, have never gone into leave without pay. I do not use any more time that my co-workers, and actually use less than a handfull of them. I need to save my FMLA rights for a possible surgery in 6 months. I will need every hour that FMLA allows for this surgery. Doesn't ADA allow protected intermittant leave? No other employees that have disabilities have ever been required to go on forced FMLA. My management do not feel this is needed and have been fighting with HR. Yet HR keeps pressing the issue stating it will protect me, they told management it is to protect their budget. Please help!