The title probably makes it sound like we have left it until my son is 5 to teach him. Its not quite like that. We have been trying to get him to wipe his bottom on his own for a while now, but he rarely does a good job. The problem seems to be that his poos are somewhat soft - a lot of fibre in his diet. If he does a really "formed" one, then there is no problem as it leaves very little to be wiped. But normally, he is unable to wipe well enough.
We have taught him to take 4 continuous squares of loo roll and fold them and then bend down and wipe. He can then get more loo roll if needed and he finishes with a kandoo wipe. He never gets it all though.
What would you do? I am at a loss of how to get him independant in this as it is not a behavioural thing. He is perfectly willing to do it, but just does not do a good enough job.