My toilet in both bathroom seems to get the water sucked out of the bowl really quickly and then backup in the shower when we wash clothes. Sometimes the contents from the front or the back toilet or the washer will come up. There is a gurgle sound when this happens. Sometimes when I don't wash the toilet will flush fine the flush the back toilet a few minutes later and everything happens again. Please help! I am on septic tank with well water

I'm not a plummer but it sounds like you have a restriction in your sewer line. Please call a plumber on this one. This is something that cannot be fixed by you or me.

Rich