http://www.bangedup.com/news/index.php?ID=200
"The good news on sphincter bleaching is that it's safer than anything involving general anaesthetics or fat-vacuuming gizmos. The bad news is that you could be in for a lifetime of skid marks. The chairwoman of the Australian Medical Association's ethics committee, Rosanna Capolingua, says the use of harsh bleaching substances could cause anal burning and scarring. This, in turn, could lead to anal incontinence or an inability to pass stools at all."
Hmmmm...yeah! I'd recommend that!