This is so sad, mostly for the little boy and anyone else who is aware of the incident in his classroom. I think it is very likely that the child has a relatively common disorder known as encopresis. This is a completely involuntary syndrome that is caused by severe constipation. About 1 in 100 children have this and yes, they may not smell good all of the time and embarrassing things may happen. It is utterly humiliating for the kid if anyone notices. The teacher needs some kind of intervention to understand these types of conditions.