Can i sue for this reason?

I was hired at a job and went in for my pre-hire stuff, filling out tax forms, etc. they said we had to go for a drug test that day, i had the flu but i went anyways. i threw up multiple times while there and the staff witnessed. i tried 3 times to provide an adequate urine sample but was unable to due to dehydration from throwing up. the testers left a message to the hiring company saying i was legitametely sick. i called in and they said i am unhirable, no matter what. i even offered a blood or hair test that id pay for myself. they said they have to stick to that policy. do i have a case?