Need help with accidents/potty regression

[Anonymous]

My 3.3 yo boy, who has been potty trained since last summer, has been having more and more accidents. At first, it was just small amounts of pee in his underwear -- he didn't want to stop playing, would pee a little then hold it until we made him go to teh bathroom. Never had an accident in school. No poop accidents since we trained last summer.

Then, this week, he's had a few full-wetting accidents, a small poop accident at home, and a big poop accident at school today. The only thing I can figure is going on is that we switched him to a big boy bed a few weeks ago (which has gone smoothly) and have been talking a lot about the small accidents, emphasizing the big boy thing. He started to say that he's not a big boy, he's a little boy, etc.

Is this pure regression? What do we do? I could handle some small pee accidents, but poop accidents at school are a different story. I can't see going back to diapers. Any advice? Thanks.