@ddljohn-- Although the cause behind black vomit is usually a rupture, there may be different causes of the rupture itself. It could be an ulcer for example, or polyps in the small intestine, or cancer. These are just a few examples.
So initially, the doctors will run a variety of diagnostic tests to not only look for and locate the rupture, but also to try and get to the bottom of what it occurred. So the treatment isn't just about sealing the rupture but also treating the underlying cause. Yes, at least a minor procedure will be necessary if there is a rupture, but the treatment beyond that will depend on the patient and what the underlying issue is.