99% seems high. We hear that question from a lot of new keepers when their snake hasn't pooped in a week, or eaten in a month, or looked up. In those cases, we usually reassure them that this is perfectly normal behavior, and a vet visit is unnecessary. We also get that question from keepers that have observed something really strange, like Ruby here. Even then, we'll often suggest that the keeper wait and see if it repeats, or if it's accompanied by other concerning phenomena. Of course, if we get that question from a keeper whose pet is exhibiting symptoms that we know are serious, for example, from a respiratory infection or a burn. Then, we'll advise the keeper to see a vet. I just wouldn't say that's 99% of the time.
I don't mean to knock going to see a vet. I just suggest posting to the forum first. It may save you and your snake the stress of an unnecessary vet visit.