On 20 February 2008 I posted up-thread about all this.
My law firm represents corporations owning many hotels and motels. The behavior reported by Sabrina, this OP, is a violation of the policies of all our clients.
There is absolutely no reason adults who need diapers for whatever reason should not be allowed to travel with dignity.
Since apparently bad conduct by front desk employees is a continuing problem, it is appropriate to bring back this topic rather than start a new one.