We have a toilet that will not flush. We have had 3 plumbers come out and it still does not flush. One said the new toilet may have had a deformity so we replaced the new toilet. One plumber said he thinks the pipe between the house and the septic tank has colasped. We had a snake run inside and out from the roof. It seems to us it may be a venting problem since it flushed better when the wax ring was worn out and it was getting air around the bottom of the toilet. Now you have to flush it 3 or 4 times to finally get the bowl empty. The shower and the sink are all tied in to the same pipe and they have no drainage problems. Any ideas would be appreciated.