I've never heard of vomiting as being separated into those distal and proximal to the ileocecal valve. I don't think that would be an important issue. What would be relevant is the difference between bilious and non-bilious vomiting. If you see bilious vomiting, you can tell that: (1) the obstruction is distal to the ampulla of Vater and (2) bile can flow into the gut.
Coffee ground emesis indicates time, rather than a specific pathology. For example, a peptic ulcer can present as an active bleeding (patient's vomit will have bright red blood), or it can present as an ulcer that did bleed and some time has passed (meaning patient's blood will be exposed to stomach acid --> vomit will have "coffee ground" appearance). It is more likely that coffee ground emesis is the result of an upper GI bleed.