While you imagine that your son might be mindful of the compromised situation he might find himself in with peers, this is not foremost on the mind of a child so young. This behavior is not indicative of any serious pathology. What I'd suggest is a reward system whereby his access to favored activities (e.g., television, video games) is gained by following good hygiene practices.
An anal fissure might be a possibility. That can make it impossible or very difficult to clean properly after a bowel movement. What can also happen with a fissure is that someone has a bowel movement, wipes up properly, but then more stool continues to leak after he/she has left the bathroom. If this is happening, it is not under your son's control, and there's really no way for him to avoid the soiling. Other possibilities might include a fistula or impacted stool due to constipation.
If he has other GI problems (you mention some issues with wheat and dairy), you might want to get him a GI work up for celiac disease (inability to digest gluten) and inflammatory bowel disease (which can cause diarrhea, fissures, and other GI symptoms).
Good luck. I hope you solve this soon.
Thanks for that information. But in case there is no physical cause (fissure or fistula, etc.), can you think of any psychological significance to this habit (power play?)? Thanks.
I have an 8 year old daughter who might (not yet officially diagnosed) also be ODD who has the same issue. In her case I don't think it is lazyness. She just thinks it is to gross to wipe herself (but for some reason does not find it gross to have it in her underware) (go figure). She does not have a problem wiping after she urinates. My husband suggested having us wipe her when able but I refuse. She will just have to get over it and start doing it herself or put up with the consequences. I do make sure that she takes plenty of baths and showers (which I still supervise). I am interested in what the doctor will have to say.
Good luck, your not alone!
Sorry, I don't have any expertise in that domain. But I'm sure the doctor responding to questions in this forum will have some good ideas.
I had a childhood friend who was always leaving "skid marks" in his undies until his mom said she would hang all his underwear on a line in the yard for all his friends to see:)
She never did of course but he was a little better at wiping himself after that.