well obviously this isn't a serious post…but for the sake of the thought experiment, if you started intentionally shitting and pissing yourself other inmates would probably mock you and/or beat you up but if it continued they would probably think you're mental, and oddly enough inmates don't tend to bully the truly mentally handicapped as long as they don't get in their way.
however i don't know that they'd give you diapers. they'd probably make you see a doctor, who would ascertain that nothing was wrong with you, or possibly just make you fucking deal with it because it's prison and you're treated like an animal in most places.