Most Stockton homeowners reach for a plunger first, and for a simple paper clog that often works. When it doesn't, the blockage is usually deeper in the trap or the branch drain, or the problem isn't the toilet at all, it's the line the toilet drains into.
Older Stockton homes add their own wrinkle. Original low-flow toilets and decades of hard-water mineral buildup in the toilet's trap and rim jets leave less room for waste to pass, so a bowl that used to clear fine starts backing up more often. We see this constantly in Downtown, Miracle Mile, and South Stockton homes.
If more than one fixture is affected, or your tub gurgles when you flush, the toilet is just the messenger, the real issue is your main line, and we'll tell you that honestly before doing toilet work that won't fix it.