I am at lost and desperate need some advice. My father, who is over 90 year old, doesn't seem to have serious Alzheimer's disease. He is okay in short memory, but he has illusion a lot of time. He also has Parkinson’s disease for 20 years. He does have issues to go to the bathroom, so he wears adult diaper. But lately, his diaper gets very wet and even pooped on it without knowing it. As you can imagine how messy it is. He is behaving like a baby. We try to ask him to change diaper, but he insists he is fine and gets very angry. I don’t know what to do. Does anyone have this type of experience? What should I do? What kind of doctor I should take him to see?