I do sometimes babysit and have babysat my neighbors kids and one neighbor has a 6 year old boy who is autistic and not potty trained.
I have changed his diapers several times and it's never been an issue for me.
I've also changed younger kids diapers too and at first I thought I would be disgusted by the poop diapers but after awhile it got easy.
The 6 year old boy is very easy to change and easier to change than some 2 year olds diapers I've changed.
He just lays down when it's time for a diaper change and I change him without an issue.