Re: Down syndrome and Autism pottie training
Yes, you are a great friend! The prior responders suggestions are great and I'll just emphacize that they should definitely call their local county developmental disabilities office and do the intake to have a case manager assigned to help this family with services. They are services out there for what you are describing and they should get on board with this asap!
If they could afford it, I would also suggest a live in caregiver who could lend a very needed helping hand to this family. I agree that the younger child is acting out because he is not getting enough attention and a caregiver could help resolve this. Even if it's for a year or two, it would be a big difference for this family.
Many occupational therapists can help families with potty training; however, if this child has both down's and autism, he may simply not be ready. An o.t. specializing in autism would be good for this family to consult with to help with some of the problems; either that or a behavioral specialist and I would think that their pediatrician would be a good source of referrals.
Keep us posted on how things are going.