7 year old step son wetting bed and playing in feces

My seven year old step son seems to be very troubled.  The mother has him on aderol (adderall) (sp?) i believe it is and it doesn't seem to help all his problems.  I feel he is misdiagnosed and needs psychiatric help.  He wets the bed and plays in his own feces, smearing it on the wall or even just touching it in the toilet.  He has a speech inpediment and has been kicked out of school already for getting in a fight.   They apparently tested his hearing and for autism, both coming back ok.  I fear there is a deep rooted problem.  His grandmother told me he seems sexually aware.  He is constantly breaking my son's toys and just destroying things.  He also shows some aggression towards animals at times, even though he loves them.   I could go on but I think I covered the majority of it.  I have a  six year old, a nine month old, and am pregnant and I fear my other kids being around this behavior.

[Kevin Kennedy, Ph.D.]

It is clear that this little boy is showing signs of serious emotional disturbance. He requires thorough evaluation and extensive treatment. His father should do whatever he can to be certain that the proper evaluation occurs.