Many weeks ago now the wife got some new bookshelves and we put on the wall. Fast forward to today and she tells the the wall is leaking?! It seems she quite precisely picked a location that landed the screws in what appears to be a 3" drain from our 2nd floor bathroom(s) to the basement. Don't know why it took this long to show up as a problem but now that I'm aware, how do I fix it? Is there a PVC filler I can use? The holes are tiny and the pipe is vertical. I imagine the waste water would prefer to go down the pipe to the basement and out of the house before coming out the holes. It looks like the water followed one of the screws to leak today. I don't think there is enough space behind the drywall to cut the section out and fit in a replacement with joints.