I'm not making a diagnosis here by any means, but this may help people understand:
http://en.wikipedia.org/wiki/Body_integrity_identity_disorder
A lack of bladder function isn't entirely dissimilar from desires to become an amputee. While I have no wishes of being permanently incontinent, I have struggled with BIID in the form of repeat self-injury and the thought process is familiar to me. The risks are different, as is the ABDL context, but this isn't a stretch (no pun intended) from me asking a surgeon to remove my arm because I am injuring it to the point where I am losing function. Short of saying that it's what's going on here, it is something to take seriously.