Now in the design of residential is not allowed to install Pissing, because the sewage pipes have not been defection design, if we have to backfill the ground to install Pissing 30-40 cm, in the original installation of the sewage outfall defection set to install squatting toilet, did not see the scene, I do not know your installation is appropriate return bend, return bends directly affect whether or not installed correctly the effect of sewage, but this is definitely a problem here, you can find professional staff to check it.