Stuck poo

My boy must have eaten something that did not agree with him. Idk what but the result has been very soft poos.

And because he is a lions head he now have poo all stuck in him bum fur.

How to I clean him while causing as little stress as possible?

I had to cut some of it out it was so stuck.

Is getting him shaved down there a thing? I just don’t know how to get him clean and he really does not like the help but I also can’t have him going around with a poo covered bum