A young girl called me to her small ground floor flat to investigate a really bad sewage smell coming from her bathroom after she uses the washing machine which is in a cupboard next to the bathroom. She said the washing machine and bathroom have been there since she moved in 3 years ago and this smell has just started. I advised her that there could be muck in her waste pipes and maybe it's pulling the water out the traps when it's emptying and to stick some drain cleaner down the plug holes. She tried this and the smell stopped after she uses the washing machine which was great. However now she is saying that after she is using the dishwasher in the kitchen the smell has reappeared in the bathroom. Any ideas? Problem is that it's one of these new bathrooms that's all tiled and you can't get to any of the pipes anywhere without smashing it apart. I have to go back there and try some stronger cleaner but am I off the beaten track?