I know there was a similar thread a while ago about blind people and when they know how to stop wiping.
I was in a public restroom and 2 of the stalls were nasty so I used the handicap stall. On the wall someone wrote "How can someone use the railing if they have no arms?" Well it made me think of how someone with no arms can clean their bum.
There was that woman on tv a while ago who has no arms and leads a normal life. But I don't thing she can possibly have the flexibility to wipe her bum with her foot.