How can I eliminate an odor from the shower drain?

Most bad smells in tubs, lavatorys and showers are caused by rotting hair matted with grease from the soap. Try this for the smell. Tonight before bedtine Take a 1/2 gallon of bleach and pour it down the drain and let set over night. Next morning ,(and this is important) flush out the drain with two large pans of boiling water to loosen the grease and flush the mess out. The bleach will make the hair slippery and began to dissolve it and the hot water will melt the grease and flush the mess away. Good luck, Tom

You didn't say, but if this is a shower that does not get used often, the water necessary to prevent odor from escaping into the shower may have dried out. Just run the shower for a few minutes. This is especially a problem in places with high temp and low humidity.

Most bad smells in tubs, lavatorys and showers are caused by rotting hair matted with grease from the soap. Try this for the smell. Tonight before bedtine Take a 1/2 gallon of bleach and pour it down the drain and let set over night. Next morning ,(and this is important) flush out the drain with two large pans of boiling water to loosen the grease and flush the mess out. The bleach will make the hair slippery and began to dissolve it and the hot water will melt the grease and flush the mess away. Good luck, Tom

I tired this with no luck. I seem to have a bit of a backdraft of air coming from the shower drain. I read another thread where they talked about shower vents, but I don't know what those are. I just bought a home in Arizona(high heat)... Could the problem be the shower venting? If so, what would be the fix.

As a rule showers are wet vented through the lavatory vent. It sounds like your shower has its own vent that's subject to down drafts. You might wish to look into installing a vent cap,(see image) to reduce it. Good luck, Tom