Oooh, I hate to ask this, but how old is your son? If he is a teenager, it may just be Stinky Boy Syndrome! We love our boys but good God they can be so stinky and vile!

The good news is there is no obvious water damage around the pipes. It could be the product he is using to wash his hair, etc? Sounds like that stuff the plumber put down the drain worked very well. Your son may just have to put some down the drain after every shower.

My son is 17 and I used to think it was just him, but now I am pretty sure he is not the problem. We have been cleaning his toilet/counter daily. He uses the same shampoo and soap I use in my shower. It isn't "smelly boy" smell. It is worse.

Oh you poor thing! I’m sorry, I’m out of suggestions! Hope you find the root of the problem!

That is curious since it is not coming from other drains in the same room - that should mean it has something to do with just that particular drain line... I wonder if something is caught in the trap that may be decomposing?

We have an issue with a working shower display in our showroom - when the water evaporates from the trap, it lets the sewer gas come up into the room . This should not be happening in your space since it is a frequently used shower... but maybe its something along those lines??

Ugh - hope you can figure this out!

I think you need a different plumber, one who is willing to check all the vents instead of being lazy and not wanting to get on the roof. :)

By the way, is it a tub? If so, check that the overflow isn't clogged.

@Fori - It is just a shower -- no tub. And yes, I am waiting to hear back from a different plumber.

In the meantime, bleach down all the drains.

We have a 2nd floor bathtub drain that connects to drain pipes that are original to our 1940 house. If we do not pour a bleach/water solution into the drain about once a month it begins to smell from the drain.

We have had it snaked by a plumber and he said there is sediment/build-up in the cast iron drain pipes, which then snags soap, hair, skin particles, and anything else that is washed down the drain when we shower. It appears that the biologic trapped in the pipe then makes it smell. The periodic wash with bleach cleanses it and helps breaks up the build up of bio sediment.

Bruce

Thanks Bruce and Bri. We will try the bleach. We are also going to run a camera down the drain lines on Monday to make sure everything looks as it is supposed to. Fingers crossed.

No problem! Try this over the weekend: https://dengarden.com/home-improvement/Phew-Whats-that-awful-smell-Could-it-be-sewer-gas-invading-your-home

Is there a toilet nearby? Have you checked if the wax ring(s) was installed correctly and is still working correctly? It might have failed and is allowing sewer gases to escape.

The plumber said the toilet looked solid. No rocking at all.

Try putting baking soda in the drain, then add vinegar; it will bubble up. Keep adding vinegar until it stops bubbling, then flush the drain well with hot water. I do this occasionally in the kitchen sink if it starts to smell.

There is a product that us called Drain care - it is the good bacteria you need to get rid of build up in pipes. Maybe try using that to get rid of whatever is being bad in there!

You were all so helpful with your comments, I wanted to let you know the outcome of my smelly bathroom. . . It took three different plumbers and a camera to finally determine that we were getting a smell from the shower drain because there was not a properly installed p-trap for the shower. This was particularly surprising since the shower was done by a well known and reputable contractor who came highly recommended and the bathroom was done with permits so the city inspector signed off on the bathroom. I sent the original contractor (from 3.5 years ago) the video from the camera guy and they came out, opened up the ceiling on the first floor and inserted the p-trap. And now the smell is gone.

!!! I can't believe they came back! They must have been very embarrassed. Congratulations on a smell gone!

@Fori - Truly mortified. When the owner of the firm came to look at the project after the repair was made, he taped a sign on his truck over his logo that said, "We install P-Traps".

Thanks for letting us know! Lucky you that the contractor stood by his work after so long. That p trap is important!

That's is great that they took care of it. Shame on the inspector who didn't catch that!

Thank you for updating. That would have driven me crazy, too.....it must feel so good to have it resolved!