Hi Betty
I know the sort of loo that you mean - where the waste pipe isn't visible at all? Unfortunately these are terribly difficult to fit as its impossible to see to connect the waste pipe fitting - although in new build houses its easier because the waste is fitted before the loo is installed, if you see what I mean. The water inlet pipe is easier though, the pipework will need to be altered to enter the cistern from below - no problem usually. If you want to fit the type of loo that has no visible cistern (because its built in behind the loo as a unit) and you want the loo to be wall hung, there is special framework that needs to be bought and fitted before this type of installation can go ahead.
John
May 2009