New toilets in the USA are advertised and required to use no more than 1.6 gallons per flush (GPF) and some use 1.4 GPF or even less. Most new urinals with flushometers use 1 GPF or less.
There are a variety of possible reasons that would cause water not to go down when flushed. The most common reasons are (1) an object has been accidently (or spitefully!) flushed in a previous flush...