My toilet backs up intermittently. There is no gurgling from any other drain in the house and every other drain works fine. A plumber said that all of the pipes are clear (no clogs or roots), and my city said that the city sewer line has very good flow too. When the toilet does back up, I plunge it and then dump 2-3 gallons of water down it. This appears to fix the problem, and the toilet works great for about 4-5 days but then it backs up again. My wife says that it is a cheap toilet and we need a new one. Perhaps she's right, but we have lived in this house over seven years with the same toilet and have never had a problem until this past two months. Is it the toilet? If it is then why has it worked great for the past seven years but now is crapping out on us? (No pun intended)