Hi there and thank you for your question. I am a licensed veterinarian and would be happy to assist you. This sounds like a neurologic problem called vestibular syndrome, which causes dogs to walk in circles and/or fall over.
It can be caused by an inner ear infection, or it can happen for unknown causes. Vestibular syndrome will usually resolve with antibiotic treatment or no treatment at all. It is important, though, to have a veterinarian examine your dog, though, to determine if this is truly vestibular syndrome, or if there is a different neurologic problem going on. There may be a problem in the brain causing this, and that may require anti-seizure medication or further diagnostic testing. I would go see a vet today for a neurologic exam, and if your vet says it is vestibular syndrome it should resolve in a few weeks time. We can hope that is all it is! Hope this helps... best of luck.
Thank you so much for checking back. I didn't see your response in time so reached out to someone else as well, you were all great. I had gone to the vet, they dismissed it, then ended-up in the Animal ER that night (as he had literally been spinning, non-stop, possibly stopped for about 3min that day, and was jerking his head all around. I started off thinking he was constipated, then was afraid it was neurological. I did give him pumpkin and metamucil during the day as well (and the vet told me to put a unlit match in his bottom, didn't work.
Got to the hospital, they put the thermomoter in him, he went to the bathroom like crazy about three times. Took him about four hours to 'start' to get back to normal though. By this morning, he was fully back to himself, so relieved :)