Stretching 
Many piercings respond really well to stretching. Many of the intimate piercings such as the Guiche, Labia and even the Prince Albert become more comfortable at larger gauges.
Some piercings do not respond well to stretching, for example cartilage piercings but not impossible.
It is very important to have your stretch by a fully experienced piercer with good knowledge of stretching. I’ve seen too many people attempt DIY stretching with drastic results. If a stretched piercing has been stretched properly from the beginning there is no reason why your stretch will not completely downsize if wished.