I understand. There is no reason that she should be less weak or less neurologically impaired after a bowel movement.
I am concerned that she has been exhibiting signs of pain. Panting and shaking can be caused by pain. Abdominal discomfort may make her too painful to stand.
Dogs in chronic kidney failure are often somewhat dehydrated, and thus they become constipated with dry hard stool. I recommend trying to get her to drink as much as possible right now. Offer dilute chicken broth and tuna juice to keep her well hydrated. You can also sprinkle 1/2 teaspoon of over the counter Miralax on her food at each meal. This can help to keep her stool softer as well.
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