Strong Odercoming from Shower drain
About 4rs ago we had a tub removed and a shower installed in the same place. The guy who did this rerouted the drain from the end where the tub drain was into the middle of the shower. For a while it was fine, but now we get a very strong sulphur odor after about 5 minutes of water running. The odor seems to be strongest when the weather warms up. This doesn't happen in any other bathroom. Have tried many different odor remedies, and chemicals that say they will work. Any suggestions on what this might be?