I don't know about the international credits. I think there are agencies that will certify your international work as equivalent to US credit, but that's a different topic. It sounds like your best bet will be to retake the classes you got bad grades in and apply to DO schools, which will replace the bad grades with better ones if you retake the classes. A few retakes and you'll be reasonably competitive for them. A year ago I was in a similar situation to yours. I had a 2.9 GPA with two failed classes after finishing undergrad in 2004. After a year of postbac work in which I took the prereqs and retook statistics, I brought my cGPA up to a 3.1. I had a good MCAT and really good ECs, and when application season came I got more DO interview invites than I knew what to do with.