Every once in a while this problem will occur, and it doesn't matter whether it is hot or cold outside: I will wash a load of clothes, the pipe (somewhere along the line) gets backed up and overflows onto my laundry room floor. Meanwhile, sooty water (sometimes with some fecal matter) will back up into my bathtub, and our toilet will gurgle and bubble air. Is there any way I can ascertain what kind of backup I might be having, and where it might be occurring? This all happened once more yesterday, and this morning after I flushed the toilet, I heard bubbling for a while coming from my bathtub drain (no back-up of water this time, though), and then all the water from the toilet got sucked out of the bowl really quickly. Any ideas? Thanks in advance!