thank you for your concern. thank God I'm not alone. I'm going to insist the child see a Dr. for possible constipation. I could never take the children, because the parents would never have it. they by the way are 7 and 5 do come to my home several times a month were I shove fruits, veggies and whole wheat down there bellies. and shower them with love while we play make believe, and silly games. I also thought about abuse, I could see emotional, but I'm pretty sure its not sexual abuse. thank GOD! My sister is well aware of how worthless the father is, but feeling pretty helpless in that department too. maybe seeing a Dr. about the constipation issue will cause them to see possible other problems too. Maybe if the dad sees that his "parenting" is causing his children too have physical problems he might feel terrible and do something at the very least about the way he feeds them. again, thank you for your support. this is never easy, but it helps to know people are reaching out with support.
How old are your babies? I'm also wondering, has your nephew seen a therapist? Children who are being abused sometimes soil their clothing in order to disgust the abuser. This could also be a control issue, or one of anxiety. I have had students with this problem, and I understand the smell.
Although you are not the parent, you are a consistent part of this child's life. You might share your concerns with your sister, giving her suggestions to deal with this. It sounds like you are thinking of taking this child in. If so, you may run the idea by your sister. If she is open to it, maybe the father will be too. If not, maybe they will let him come to your house two days a week or so.
I know how hard it is to see all of this turmoil and feel helpless. It is important that he see a stable environment and know how it works.
Good luck and God bless