I also teach bum wiping during the potty training stage. Once they are fully trained, i usually don't wipe their bum as they go to the washroom throughout the day when needed and don't always tell me if they even pooped. If they do call me, I'll go and encourage them to wipe and make sure they don't need help. I don't want poop streaks on the toilet, floor (I have one who completely takes his pants and underwear off and than sits on floor to put back on lol) or even their underwear if I can help it. Right now I have a 2.5 yo and two 4 yo's who are trained and I almost never have to wipe bums.