My mom fell Thursday without injury, about an hour later she was soaked with urine. Next day she was incontinent with her bowels. Just like that. I called her DR. and they said to take her to ER. CT scan normal and no infections. She has Parkinsons with dementia. She is more "out" of it now.
She could have sustained a concussion if she fell on her butt and the force travelled up her spine to her head. No simple answer. I would put my check mark next to "all of the above"