While you're waiting for an expert to reply, let me suggest that the wire was indeed a clothes hanger some previous owner, perhaps, stuck in there to loosen up a clog. He lost it in the pipe, decided it wasn't worth retrieving, and sold the house. Now that it's out of there, any debris and disgusting gunk it might have been holding back is now free to travel to wherever the pipe leads -- apparently your bathroom. I'd take off the showerhead and run the water full bore through there for a few minutes to allow the pipe to clear. You may also have to remove the aerator on the lavatory faucet and possibly disassemble the toilet valve to clean them out as well. If you ultimately call a plumber, save the "coat hanger" and some of the gunk for him or her to look at -- they might provide clues to determine further action.
I'd also be curious as to how the painter/plumbers "patched the hole".