There was a clog in the bathroom drain so I took off the connections under the sink to unclog.... I cut the sheet rock to get to the pipe to see what I was dealing with I cannot find where the drain pipe went into the ground (or where the pipe actually broke) coming out of the ground. I looked and looked. The obvious answer is straight down... I thought I was going crazy but I cannot find where the spot where the pipe broke..

I had purchased flexible couplings to reconnect the drain pipe but without seeing where the pipe broke I cannot fix. THe foundation is cement but the water supply lines that all come from the ground so the drain pipe would too, right? I am hoping someone can give me some insight here.. Thanks.