My wife's older Trek hybrid, steel-framed 730, has 2 drain holes on the seat stays, near the rear dropouts. This bike has been on the back of our RV, on a bike rack, for 3000+ miles, being used at various times on this trip. When I took the bike off the last time, moving it on the back wheel with the front wheel up, two streams of water shot out of the drain holes; a lot of water drained out. I've noticed some rusty water in the past, but this was extreme (although this water wasn't rusty).
Should I be concerned? Is there something I should do? Should the bike be considered "suspect" in terms of the frame (I don't know how long this has been going on).

Opinions please. Thanks.