Just purchased home. We are having a problem with flooding in the basement. An interior waterproofing system was installed before purchase. It appears the flooding is coming from under the door. We had a plumber inspect the outdoor drain and was told the pipe was full of rock and debris - basically the pipe is deteriorated (1970's home). He suggested installing a sump pump outside. Is this the best option or should we re-run the underground pipe? Will the sump pump freeze in the winter? What happens during power outages? Looking for the best long term solution. Thanks.

So I took out my old toilet, was cleaning the old wax off the flange when I knocked one of the plastic caps that go over the toilet screws on the floor down the toilet drain hole. Now I'm worried it's going to cause a clog. Do I need a plumber to suck it out somehow, or given (hopefully) the PVC drain pipe goes all the way down from the second floor to the drain line down in the basement, will it get flushed out once I put the new toilet on and flush water down on it? The toilet drain happens to feed directly straight down from the second floor to the basement, where I'm guessing the plastic cap is sitting right at the elbow in the basement ceiling (just below the first floor) where the pipe is 2.5" or 3" (sorry I don't know the standards) before it traverses about 3 feet to the main drain pipe which I guess is 4" down to the sewer. I know the plastic cap is small enough to traverse through the piping unless the pipe diameter is less than 1-1.5 inches, is what I'm guessing what the cap diameter is. I'm hoping a couple of flushes will push it out, or should I run some water with a hose through it to be sure before I put the new toilet back on?