Well not really an accident, my 6 year old son lately has been, what seems as pooping in his pants? When we see him push, we ask do you need to go to the bathroom? He states "no" while straining. We explain to him that he needs to do this in a toilet and he says okay but it continues. Is this a possible medical problem?

Concerned.

I don't think it is a medical problem. Sounds like he is afraid to admit he is having a bowel movement.

Tick

Is he constipated. Perhaps it is easier for him to push when he can reach the floor. Ask him. Perhaps provide him with a stool to have some leverage. It it continues I would contact his pediatrician. To old if it just pooping for the sake of pooping in ones pants.