okay, this is something we have been trying to get fixed for months! when we are taking a shower, the toilet bowl will start to bubble, then empty. drains have been cleared repeatedly, and 10ft of pipe replaced, but still this happens. it doesn’t happen everytime we take showers. HELP!!!
The vent being plugged could not be a factor,unless you also had a sewer problem. Either you have a malfunctioning septic system or the main drain is still not clean, regardless of how many times it has been snaked. Perhaps the problem is inside the house.