While trying to remove a broken pvc commode flange, the drain pipe broke off approximately 3 inches down inside the concrete foundation. We bought a twist and seal flange that has an extension that goes down inside drain pipe but it did not go far enough to cover missing pipe. I feel that it would work if it had a longer extension piece. Does anyone have any other ideas of what we could do to fix this problem.
Thanks.

If it is 4" pvc, a 3" pvc couple fits exactly inside. If it is 3" you will have to open the floor and either replace the bottom fitting or use a 3" couple to extend it back up.

They make these Twist 'n' Seal flanges about 6" long. Go to store that caters to the trade. They will help you...