All toilets created equal?

[jumblejim]

I've got 3 standard U.S. residential toilets in my house--all different models but all bought at the same place a few years back. Two of the three work just fine. But the third one stops up with solid waste probably two out of three flushes. (It usually clears after 2-4 extra flushes, but sometimes requires a plunger.) My contractor assures me that the waste pipes into which the toilets empty are all the same size, so it seems clear it's an issue with this toilet. Looking at the S-pipe outline on the lower side of the toilet, it seems as though the path from bowl to floor waste pipe is pretty similar on all three toilets. But only this one gets stopped up. (And yes, the same people are using all three toilets.)

Are the internal workings of the bowl-to-waste-pipe path standard from company to company, or is there a wide range of variations? How can I replace this toilet and be assured that the same problem won't result?

[pushkins]

I'm not a plumber, so I'm sure there might be someone that disagrees BUT there are toilets and there are toilets. I never buy cheap toilets..EVER..
I like Toto they work well and I haven't come across one yet that doesn't flush extremely well, I also have a penchant for Kohler Cimerron range of toilets, both have 2" traps and something I think is very important, fully glazed traps. Many (if not all) cheapy toilets don't have glazing throughout the traps, this can cause hangups.
Any bathroom renovation I do consists of removing toilets and replacing with quality ones (we donate the old ones cleaned of course).
Never had a problem.

[Redwood]

All Hail Toto!

Great toilets!

The Toto Drake II Model # CST454CEFG ADA height toilet with Sanagloss and Double Cyclone Flush and is probably the best deal in the Toto Toilet line today

[HayZee518]

check the wax seal. some have a plastic reducer embedded in the wax. your other two mayhave just the wax ring.

[Redwood]

Also run an auger through the toilet there may be something lodged in the trapway...