Chiari malformation (compression of the spinal cord at the base of the skull) can cause your bowel and bladder symptoms. A fall can aggregate this condition and cause further dysfunction of the cord.
An MRI of the brain should include the cervical spine as these Chiari malformations can be associated with a syringomyelia (a swelling of the middle of the spinal cord).
You need to get into a base of skull specialist to have a full workup. Do not hesitate on this.