Dealing with Lucas' shit

Literally, I need to figure out how to deal with his shit.

Today was the 2nd time that his school called me saying that he had an accident with #2 in his pants. He says that he still doesn't poop at school. (Except there was one time that he had said he had a stomach ache so one of the teachers took him to the toilet and they made it just in time.) He's never had an accident with pee, just both times with poop.

Anyway, the last time, it was all over the inside of his jeans. I just about barfed as the teacher handed me the bag. I could barely drive home with it in my car and just put it in the outdoor trash as soon as we got home.

This time it mostly got on his underwear (which I promptly threw out along with his socks), but some on his pants and shoes. I know my mom would tell me to wash it in the toilet. And that's what I was going to do, but the stench was so strong! I used some paper towels to wipe up as much as I could, applied generous amounts of Spray and Wash and put them in the washing machine on hot.

Is there a better way to deal with his shit?