FMLA rejected my leave after fistula/abscess surgery

Apparently my surgeon didnt "provide sufficient medical facts to support the need for leave" I guess a large gaping hole in my ass isn't good enough? Or the fact that I was on hydrocodone and phenergan all week for pain and nausea (from the pain meds)

I work at a bank. There was no way I could sit all day long after that surgery. And why would you want me handling money while doped up on narcotics?

Edit to add:

I was only out for one week. I came back to work as soon as I could stop taking the pain pills and switch to Tylenol. I'm still changing dressings in the bathroom 3 times a day.