Respected user , hi I evaluated your query thoroughly.
*yes damage to splanchnic nerves are definately going to give rise to said
symptoms.
*Many neurological ailments take long time sometimes months to years
to resolve .
*Have to depend on catheterisation for
urinary retention, no other way.
*For bowel retention , bulk forming laxatives, high fiber diet and if needed
manual evacuation of stool as necessary.
*Keep the patient ambulatory till possible.
Hope this clears your query.
Thanks for using Health Care Magic and reviewing my answer.
Wishing him fast and speedy recovery from the same.
Regards.
Bye Dear take care of him.