Hmmm.... so much to talk about on this icky thread. LoL
First; other kids poops= bleccchhhh. (I am not sure how to spell that noise, but you get the gist)!! And some kids totally smell worse than others. I had one little guy whose mom insisted he needed extra iron. His poops were soooooo stinky. The only good thing was that they were also rock hard like little pebbles, so didn't need 478 wipes to clean up!!
When I was pregnant, and therefore gagging at just the IDEA of some odors; I would take a tissue and stuff it up my nose. If it was going to be really bad (you can tell, right?!?) I would also put a dab of Vicks Vaporub into my nose. Hey, it works for coroners and medical examiners, right?

On the idea of a 4 year old not pooping: I also think that if medical issues have been ruled out, and all the kinder, gentler methods have not worked (ie; stickers and rewards, etc) then it's time to crack down. If it is known that the child CAN use the potty, and it's not a terror issue (some kids get phobias), then it has definitely become a control issue. Honestly, I don't think I would do a diaper (or poopy pull up) for a kid that age. Flat out gross. I don't see any schools letting a child that age wear diapers, either. My cut off is more like 3, which I know can be a little early for some, but I personally think that 3 is PLENTY old enough to use the toilet.

As for not wiping the bum; if mom and dad haven't taught that, then I damn sure would be!! I get it if they are little (like, 2!) and just started the potty thing. I remember my oldest sitting in the bathroom yelling "Mooooommmmm! I need a wipey bum". (Awww, that seems like so long ago now, *sniff*). But it becomes a necessity, no??? A collleague of my husbands brought his kid to the office one time, and he went to the washroom and shortly afterward started yelling for his dad. Turns out, he needed dad to come in and wipe his bum. He was 6!!!!!! I was beyond disgusted.