What is wrong with my belly button piercing? The skin that the bar is through is very red and sore. (Photos)

I have had my belly button pierced for about 3 years now.It healed well and was fine up until a few months ago when it became infected.It healed great but it’s recently started to look like it’s rejecting.I’ve had a lot of piercings and never had this problem before. The skin that the bar is through is very red and sore.There’s no pus or blood it’s just very painful and the skin where the bar is through is very raised from my skin.Any advice on why or what is happening with this would be great