My dd5 had surgery in December and I noticed several styles in the giftshop at the hospital - there were a variety of different ailments as well. My dd has a very rare bleeding disorder so I was not able to find a complete bracelet there but I was able to find several beaded bands for the one she already has.
I know CVS has a band that you write the information on a sticker that goes inside of the band. I bought one of these for my ds7 a couple of years ago (asthma and allergic to latex, milk and egg) but because he could take it off himself, he lost it (or rather I think he gave it away) and couple of weeks later. He now wears the standard stainless steel band with a clasp that he can't remove.