At work, we snake a lot of residential sewers. Next to roots, tampons are usually the culprit. I'm used to picking them off the cable now, but my first time was a real eye opener. Especially in a home with multiple women all on the same schedule. I've pulled out piles the size of a basketball.

Also, cat litter is not flushable either.

It will cost you several hundred dollars to have someone fix it. And be aware that companies like Roto-Rooter will often give up after a few minutes, and push you into a full sewer replacement. 9 out of 10 times, a skilled operator can open a line with a snake.