My dog temporary lost control of its back legs and then have gotten them back. Legs are very stiff real wobbly walking. She is now just sitting there shivering she had diarrhea when this all started?

This sounds to me like a partial seizure. They are not always how you imagine them, with the dog falling over and shaking - that would be a full one.

There are three phases that a dog having a seizure will go through.

1. Pre-ictal – Your dog might seem agitated, nervous or restless. He could start to pace, come to you for a cuddle, dribble, hide or whine. These signals take place just before the actual seizure starts and can last between a few minutes or even hours.
   
2. Ictal – This is when the dog is having the actual seizure.  If it is a full seizure, your dog’s muscles will contract in a spastic like motion which is uncontrollable.  Your dog may fall over, and his legs may appear to be stiff or paralyzed while he is having convulsions.  Your dog might
   also lose control of his bowels or bladder. Dog seizures normally last between a few seconds to a few minutes.
3. Post-ictal – Your
   dog’s seizure is now over, but he will still be confused at this time.  He may be panting and dribbling a lot, and might appear to be unable to see after his ordeal.

With a partial seizure, the dog can lose control of one area of his body, sometimes his face, or (possibly in your case) his legs. As above, bowel control can be a problem at this time.

The best thing to do is to take him to a vet for a checkup. If it was a seizure, he will need tests but can be put on drugs much like a human epileptic would be.

The other factor to consider is his age, dogs can go off their legs through old age but with the symptoms you describe it doesn't sound like that.

I really hope your dog is feeling better very soon, I know how worrying it is when a pet is unwell.