IPhone 5s apps deleted from phone after app updates, can't download them again.

i Did an "update all" today and a selected few didn't auto update. I had to click their icon in App Store update list, which took me to a screen with the description and reviews etc. there I could hit "update." Now I go to use those apps and they are not on my phone anymore. When I go back to App Store to try and download again, the "get" button is grayed out and I can't download. Any suggestions?