Premature posting. I wanted to add more to the above post before I submitted it. The "U" part of the trap is what holds water. If you look down the drain you might be able to see a portion of the pool of water that is held in the trap. The odor could also be hair and oil conglomeration that has been brewing in the waste pipe for a while. Hair from your head, oils from shampoos, conditioners, and soaps. I've snaked some waste pipes and had slugs of "stuff" several feet long come sliding out of the waste pipe. Ugh. On occasion I have seen vent pipes on the roof plugged up. Anything from bird nests to frost build up during cold weather. If the house is on a slab, an area about 18" square around the proposed drain location is normally boxed out. No concrete is poured in the boxed out area when the slab is poured. The drain pipe is piped into that box. Later the plumber can come in and set the trap in the boxed out area, then fill the boxed area as the shower pan is built. So...it could be a dry trap caused from lack of use/evaporation. That's the most common in a seldom used bath. It could be a blocked vent pipe. If your vent pipe is blocked, sometimes water sent down a drain in one part of the house can cause that same trap or a trap in another part of the house to siphon dry. An indication of that problem might show itself when you flush a toilet upstairs and see the water in a downstairs toilet bowl shimmer or bubble. Upstairs laundry can cause that as well. Siphoning can also be from the horizontal pipe extending off your shower's drain being too far from the vertical pipe that vents the shower. It could be a hair ball that's been smoldering on the pipes for a while. Do you get a good pull from your exhaust fan? When it's running, is there enough suction to hold a paper towel or a section of toilet paper up against the grill? Mongo

I feel your pain soonbslim. I have a fragrance issue and DH has super sensitive skin. DH is a mechanic so he gets greasy, plus he enjoys working outside alot in his off time so his clothes get very sweaty & stinky. After trying all the major brands on the market in their various forms including the Free & Clear ones and the "baby" detergents, we finally found Charlie's Soap Laundry Detergent--who knew it was made practically in my backyard!?!. The powder form seems to work best for us in our 7 yr old Kenmore front loader. Rinses clean, fragrance & dye free, low sudsing, cleans well & clothes come out soft with no fabric softener required. You may want to give it a whirl. Hope this helps! Here is a link that might be useful: Charlie's Soap

mojomom……I so remember this and how frightening it all must have been. I know I responded to it but must not have hit the submit button because In scrolling down, I wasn't there. It was so sad to see Patti43's name just six months ago. She must have been so sick at the time. I'm so happy to hear that all is going so well. Thanks for the up date……..speaking of things that bring a smile to your face, this is one of them.

Hi Pat, I decided to try Costco's exclusive ALL F&C formula as my MIL has been using it exclusively for several years and she swears by it. They do a lot of laundry in her house (6 adults) and I've been paying attention to their clothes. Everything they wear always looked clean, stains were removed from tablecloths, clothes didn't appear to wear too quickly, etc, etc. I took the plunge and finally bought a bottle which runs for $10.99 on sale every other month or so for a huge 158 load bottle. I've been very impressed with it's performance. It gets my laundry clean, soft and well-rinsed. I'm still on the fence as I haven't tried it yet on everything...Haven't washed my napkins or bedding with it yet but so far it hasn't let me down. My 96-load bottle of Tide F&G is nearly empty, so I'll be using this ALL liquid for mostly everything soon. I also have Tide Purclean Free which I use on laundry that I don't want OBs and ALL Free powder for heavy duty loads including workout clothes and microfiber cleaning towels.