I just wanted to know if you take a shower and water comes into your basement from the drain, what kind of water is it? The water was soapy and didn't smell bad at all. I asked the plumber when he came over to fix the problem, and he said it was sewer water that was stuck in the trap. So, I am confused. Is the water dirty contaminated toilet water, or is it water from taking a shower? I want to know because the water touched some stuff in my basement, so I'm thinking about throwing the stuff out. Thank you for your time.

It is most likely the shower water, although some trap water may have come back too. All water runs through the same pipe, toilet, vanity, tub and shower. As far as the items touched by the water, unless seriously soiled, wash them with HOT water and they should be OK (assuming they are clothes or fabric). If paper better to toss, cans and glass just clean. You probably have a clog after the floor drain and the plumber should snake through that. )

I asked the plumber when he came over to fix the problem, and he said it was sewer water that was stuck in the trapYour plumber was lost so he simply blew smoke up your skirt, Shower drainage does, indeed, come from the trap.

I am confused. Is the water dirty contaminated toilet water, or is it water from taking a shower? I want to know because the water touched some stuff in my basement, so I'm thinking about throwing the stuff out. It's not all that contaminated. It's just the runoff that you showered with.
What type of shower do you have? Plastic walk in enclosure or custom tile? If a plastic enclosure does the floor give or flex a bit when you step into it? Back to you, Tom

It's actually a bathtub and there is tiles on the wall. It's an old house, but I've been living here for two years and I never had water come into my basement, even with two hurricanes. So, I was very dismayed to see the water, and then even more upset to find out it might be sewer water. It just grosses me out.

Actually it would most likely be considered "grey water" not "brown or black" sewer water. Shower water is commonly used as watering for plants.

Can you tell us where the water comes from? The drain lip? The trap? Other? Back to you, Tom

Sewer back-up is sewage. What goes down the shower drain, kitchen sink and toilet all go to the same pipes. Spring is a common time for tree roots to grow quickly and get into sewer pipes. Don't freak-out and throw all your stuff out. Disinfectants like bleach and soap can clean-up your stuff.