Integrated Units by Flushing System
Gravity Assisted Flush Systems
Most toilets today are gravity assisted. This means that there's a water tank that sits above the bowl. The toilet uses the power of gravity to operate the flush. Integrated units that offer gravity flush systems are a bit tricky, because the tank sits behind the bowl, not above it. There are a few integrated units that offer this flushing design. The internals of these integrated unit's tanks are more complex than a traditional toilet's tank because it has to make the very most use out of the gravity it has to work with.
Pump Assisted Flush Systems
Higher end integrated units tend to offer pump assisted flush. These flush systems are more powerful because they don't rely on the limited amount of gravity to power the flush. If you're looking for an integrated unit with a powerful flush, a pump assisted flush is the way to go!