For about the past week, everytime .Noah has a poopy diaper, he sticks his hands down there while .I'm trying to change him!

It's almost impossible to keep his hands away while his butt is in the air and .I'm trying to wipe him. He has been such a good baby with getting changed up until now. (He's about 10 1/2 months old now.) He kicks and screams almost everytime. Any suggestions on how to keep his hands away? I've tried giving him a toy to hold and it just ends up in the mess along with a hand!