You didn't send your medical exams with the application, you sent Appendix C at the end of the the region specific instruction form for Latin America (http://www.cic.gc.ca/english/pdf/kits/guides/3908e.pd) which your DMP signed. The actual medical results were sent from the DMP that conducted the tests to Ottawa Regional Medical Office (unless Bogota has theirs go to the Port of Spain medical office, I don't know...), and Bogota received them from Ottawa once they requested them. As far as what e-cas status changes mean or what prompts them to me, it's kind of like the million dollar question. You can certainly read their list of FAQs for e-CAS (https://services3.cic.gc.ca/ecas/redir.do?redir=faq_ecas&lang=en&app=ecas) or read the tables that are at the bottom of the screen when you log in to e-cas, but the point is that you should not treat it as representative of where your application is at that given point in time because it's not. Posting in the Bogota thread will give you a better idea of how that VO processed apps, as well.