good points by all above. How long has he been on the meds? Did the problem start after he started the meds, because sometimes the meds can be part of the problem. What meds is he on - if you don't mind sharing?
Gosh, I'm really sorry to hear this. Do they think this is related to the ODD? The smearing it is where is a bit disturbing, I'm sure, for you. Now, I have an 8 year old. One thing that was different about him verses his brother is that he actually needed some coaching in order to wipe properly. Are you positive nothing like that is going on? Does he have constipation or anything like that in which he then isn't sure when he is really going to go or may not be totally finished when he pulls his pants up?? Just curious because things like that do happen and more of a natural way that the things going on with the bathroom stuff would occur rather than willful smearing of feces.
Just wondering about that.
The very first thing you need to do is have your son evaluated by an MD. These behaviors can be caused by a medical or an emotional problem. Once evaluated by an MD, you will have a better idea of what you are dealing with.