We remodeled our bathroom with tiles and marble in the shower last January.
Yesterday my wife took a shower and the water instead of going down the drain started coming up. I tried to pump the drain and debris and sand (maybe grout) came out. It took a while before the water went away.
I decided to take a shower in the other bathroom and, right after, that sewege water started dripping through the ceiling into the dining room downstairs.
The plumber that came said that all upstairs is clogged up because of the debris, sand, etc., but the builder that remodeled the bathroom said that's not the problem.