I recently purchased a home, the people had a shower built into the basement. I am getting a fowl smell coming from the shower drain when I use the washer. I started to look into this a bit further, I found that the shower doesn't have a p-trap installed, nor can one be installed as the abs piping is cemented into the ground and there is only 3" of abs pipe before the shower base. If I put water down the drain before the washer is used the smell is not there. Is there something that can be done to get rid of this horride smell. Other than remove the shower and cap of the pipe.
Please let me know. Thanks Trevor

Previous home owner was no plumber. The right way to fix this is to rip it out and tear up the floor. If you want to go this route I'm sure you'll come back with more questions. For now do one of two things. Semi-permanet put duck tape over the drain. Short term, get some red rub gasket material at the hardware store. Cut it the size of the drain trim and grease it with vasoline or cooking oil. Place it on the drain trim and give it a slight twist to seal.