Hello,
I have a problem with a sewage pipe that is coming from an internal toilet. Every so often there is a strong rotten eggs smell coming from the sewage bend in the attached photo when you stand beside it outside. Its not there all the time, but probably correlates with about 10% of the time when someone does a number two in that toilet. It seems the smell is coming from where the bend and pipe join. Should this be happening ? Is it that there is a problem with the seal in the bend ? any tips to fixing this problem would be much appreciated.