During my very first visit to the US (during my honeymoon, to be precise) I had my very first, very embarrassing experience with a plunger. After all, it happened at my mother-in-law’s house. As it happened again at a hotel in Las Vegas a few years later, I still didn’t understand why I clog a toilet in the US, but never have before in Germany.
I moved to the US many years later and bought an older home. As the drought in Georgia worsened in 2007, I noticed that the toilets in our home used 3.5 gallons for each flush. I started looking around in home improvement stores and was stunned that all toilets available used 1.6 gallons for each flush. As toilets with the option of using very little water for flushing No. 1 have been available in Germany for a very long time, I could not believe I couldn’t find them here. So after much research, I finally found Caroma Dual Flush toilets and decided to spread the word and help Georgians flushing less water and money down the toilet. After I learned why Caroma toilets work so well with very little water, I realized why American toilets clog. So finally, 16 years later I realized that there was nothing wrong with me, or my diet, that I clogged a toilet on my honeymoon!
Standard US toilets clear the bowl with siphon technology, so the waste in the bowl gets pulled into the drain and out into the trap way. In order to create this siphon action, the trap way needs to be as narrow as possible, usually around 2 to 2 3/4 inches. You can see how siphon vs. washdown technology works here
Although most of the time this flushing method gets rid of the waste efficiently, there is a tendency for blockages to occur in the toilet trap way.
Australian and European designed toilets use a wash down method which “pushes” the waste down, instead of “pulling” it. This is why European toilets have a larger diameter trap way which results in less clogging.
One drawback of wash down toilets is the smaller water spot in the bowl, which can result in “skid marks” happening on occasion. So it really comes down to a matter of personal preference. If you are comfortable with getting out a plunger to unclog your toilet every now and again, then stick with an American style toilet. If you have issues with clogged toilets and don’t mind using a toilet brush every now and then an Australian or European style model may work better for you.