Squibsy - "What in practical terms might a parent - or anyone else - be doing/not doing to a child so he/she is exhausted / hungry / thirsty ... OR, does this sound like an underlying health issue? Diabetes?
Yes, this is exactly what it sounds like. As I said in my post above, these are exactly the symptoms my daughter presented with just before being diagnosed. I urge your son to take appropriate steps around this
Or even, in practical terms, how can DS flag up any health concerns to the other parent when the other parent's immediate response is to threaten to withhold contact?"
Approach the mother, putting the child's welfare at the forefront, and not being accusatory in any way, around her parenting. He should say to her something along the lines of - "I'm a bit worried about Johnny. He seems so tired when he's with me. I've also noticed an odd, sweet kind of smell around him, and he's so thirsty all the time. Have you noticed any of this when he's with you? I have been told that these things could possibly be an indicator of diabetes. What do you think? Should we, putting his need ahead of our fractured relationship, take him and get him tested, just to eliminate that as a possibility. Especially as it is a life threatening condition if it's not treated
If she refuses, then I repeat that your son needs to take his son to a GP (or possibly, a pharmacist can do the test) for a simple finger prick test and/or urine test, to establish if this is causing the problems you describe.
If that's not the issue, then you can think about what else might be causing it. But I don't think lashing out at the mother, and accusing her of drugging the child to sabbotage contact, is going to be helpful.
Withholding contact is in breach of the CAO and should be returned to court for review.