3 1/2 year old afraid of pooping on the potty

My son is 3 years and 6 months old.  He has been trained to pee pee on the potty for 12 months now.  However, he absolutely refuses to poop on the potty.  He wears underwear all day long and when he has to poop he asks his Father or myself for a pull up, or he will go and put a pull up on himself and poop in it. He goes and hides while pooping, and when he's finished he comes and asks us to change him or clean him up.  My little boy will not even sit on the toilet, when I try to at least get him to sit on it, he has an absolute meltdown- he acts as if he is petrified of sitting on it.  When I try to talk to him about the situation he says "I can't poopy in the potty."  I ask him why he thinks that he "can't" and he just reiterates that he cannot do it.  He is in preschool and has himself on a schedule where he will wait until he gets home and poop in his pullup.  Until recently the preschool did not even realize that he wasn't poopy trained yet- but last week he must have gotten off schedule and had an accident at preschool.

I do not know what to do, you name it and we have tried it, Bribes don't work, big boy talk, nothing... he is just plain petrified to sit on the potty. My little boy is extremely bright and way ahead in all other areas except this... I don't kow what to do... Please Help!!!

[Kevin Kennedy, Ph.D.]

I did not realize you were not using a potty chair. Yes, absolutely do so.

[Kevin Kennedy, Ph.D.]

Continue to be patient - the more invested you are in this developmental achievement the more your son will delay. Relax - there's no rush, and many children are not completely potty trained at his age. Employ books and videos on the topic to increase his interest, just be judicious in the frequenxy of their use. And be sure to reward him for any time that he does use the potty.

[mommy_of_2_2011]

Is he maybe afraid of the toilet flushing? Try showing him that. And if that doesn't work try getting a potty chair???

[alishann]

Thanks for your input :)
We have a potty chair that we try to use in addition to the toilet. That's the problem though, he won't even sit on it.  When I try to put him on it he has a meltdown and is coming up off the toilet/potty chair before he barely touches it.  He pee pees in the potty and has for a year now, and flushes when he's finished.  He says he "can't poopy on the potty" and absolutely refuses...