HelloCustomerand thank you for allowing me the opportunity to discuss this with you. There are many things going on here that are concerning to me. I do believe that they are all related. I believe that he may have some form of emotional disorder that is causing all of these behaviors. Has he seen a child psychologist? This would be my first thought as the other issues are mostly psychological. Has he seen his family doctor or pediatrics doctor? Have you addressed these things with them? I would take him in and have a complete evaluation completed.
As far as stopping him from going in his pants, whether it is a bowel movement or urination, it is very difficult for you to stop this. Any type of method that you are trying to do will only cause him more emotional distress. What needs to happen is that he needs to see the doctors there and start some behavior modification. This is a difficult and frustrating problem and I wish you all the best with it. You can overcome this,but first you need to find the proper diagnosis and then get started on the proper treatment. Good luck and thanks again for allowing me to answer this most distressing question.