I am a renter on the bottom floor of an old 2 family apartment house. Since moving in 3 years ago our bathroom sink has had black sludge with a sewer-like odor (similarly described by Asker Victor: "smell coming up sink drain pipe".) It happens about 1-2 per week. However, ours pops out of the drain with some force and each time I've heard the pipes going in the apartment directly above. The plumber provided by the owners of the house suggested cleaning the pipe beneath the sink. Most recently, the evening after I cleaned with a Zip It tool, it exploded out again. I plan to try the remedy given by Speedball1 but would like info on the reason it pops out with force.

Thank you,

Ariane

It is exploding because the clog is downstream of you. Both apartments come together and its clog out there beyond the connection. When folks above you flush it backs up. Your landlord has not hired the sharpest knife in the drawer. Start raising cane with the LL, it is illegal to rent in this condition. A call to the health department will cost him far more than a licensed plumber who owners a sewer rodder and knows how to use it. That is the correct approach.