Hello I need some help in my house, There is a very strong odor originating in the downstairs bathroom. Our home is 2 years old and we have a septic system. It smells like a out house! Down stairs. There is a pipe clean out leading into the bathroom but the source seems to come from the toilet and the shower drain and actually comes upstairs into my master bathroom I assume coming up the pipes the smell isn't there all the time but these last two days very bad! Candles don't help I feel something was not sealed properly help! Kathleen

The toilet and the shower should both be trapped to prevent sewers gases from reaching the interior. Any chance the shower in the basement has gone without use for several months? The water in the trap may have evaporated. Pour a few cups of water into the shower drain and see if that helps. You may also have a wax seal under the toilet that failed. Try the shower drain water first then consider replacing the wax seal.