Late last August (2005), when I achieved my initial weight loss goal, I got my industrial piercing. It's one of my favorite piercing types because it's non-conventional without being too "look at me."
In March, after going to Vegas for a conference, I got really sick. This irritated the piercing very seriously and the skin around it grew little bumps around the holes. I thought over time it would correct itself, and after doing the sea salt washes, tea tree oil and most recently, nothing at all for several months, it hasn't gotten any better. It got irritated and bled a little while on vacation last week.
So I have to make a decision that is disappointing any way you look at it. Either I take it out, which will suck because I like it, or leave it in and probably deal with the continued issues. It's a no-win any way you look at it, and it kinda bums me out.
Well, the initial question is whether or not the bumps would subside on their own or require some minor surgery. And regardless, there will be scar tissue that will probably not ever go away. So I guess the short answer is, no, re-piercing is probably not a good idea.
I remember reading somewhere that the scar tissue thing is the reason piercers recommend to women to not re-do nipples if they take them out and heal, because the additional scar tissue can interfere with breast feeding (and you can nurse with piercings just fine). There are a lot of piercings that have little consequence if you decide to take them out (tongue, lips, nostrils, septum) and others that are likely to leave a mark (cartilage, eyebrows) no matter what. Nipples and navels probably fall somewhere in between.