My bathtub exhales a nasty odor after I shower. The odor last a few to several minutes then it goes away and it only comes back after the next shower. I do not have a clogged drain. The water drains very well. In fact, when I bought this house 6 months ago, the drain was a little clogged but there was no smell. Once my husband unclogged it, it was when we started to notice the smell after showering. I tried using products to kill mold, bacteria such as bleach, vinegar and boiling water. It seems to work for a few days then the smell comes back. My husband is convinced that there is no p trap. We can hear the water drain very far down the pipes, while that does not happen to our other bathroom. But if there were no p trap, wouldn't it smell all day long? Like I said it only happens after we shower. I appreciate any help.