We've always had problems with clogged pipes. The last one, about three weeks ago, we had to call a plumber. It was so bad that our washer wasn't even draining. So this plumber ended up putting his line (?) from the kitchen to the other side of the house, ending with the second toilet. He was telling me about how he thinks we have a busted pipe because he can't get through. When I went to check things out, I could hear his line banging against the toilet, like it was trying to come out through there... and it sounded horrible... the metal against the porcelain. I told him a few times what I was hearing, and he just nodded his head and kept going. He's the pro, right? He finally pulled it out, and his tip was all bent. I paid the bill and had a cleared pipe. However, now when there is an extended time the water is running, shower, washer, there is this groaning noise from the last toilet. It lasts a few seconds... but I'm worried that the plumber either made our situation worse, or he broke something. What could possibly be going on?