I agree that how "procedure heavy" a place is should probably not be at the top of your list of things you look for in an IM program. Not that it shouldn't be on your list, but there are a lot of programs where you could do plenty of central lines and LP's, if that is your thing. I don't personally know of any IM programs that let house staff do colonoscopies, althought there are fp programs that still do. Colonoscopies are generally done by GI fellows, GI attendings and general surgical residents (the latter are apparently required to do these as part of their training...which seems weird to me).
I agree with the comments above that you should look at programs that have more ICU months if you like procedures. Also, county hospitals and VA's do tend to have more procedures. Don't pick a cushy community hospital with lots of rich, "private" patients b/c the attendings are not gonna let you touch them.
Internal med isn't really a very procedure-heavy specialty, though. I do think it would help us to know what subspecialties you are interest in, and/or maybe you just want to go into private practice and want to be "ready" from that standpoint.