Well it is difference in name. Both are Graduate degree in Medicine. Different name and abbreviations are used in different countries.
Full form of MBBS is (Medicine Baccalaureus and Bachelor of Surgery) where Full form of MD is Doctor of Medicine. Both graduate degree are awarded for physician and doctor.
In USA it is called MD, as Philippines follows American Education System, they also called MD.
In India MBBS is done after 10+2 where in Philippines it is done after BS (Bachelor of Science) as Philippines follows 10+4 System.
But for 10+2 students (like in India) one has to do BS program from Philippines before doing 4 Years MD. BS is generally is having 10 Months to 18 Months Duration, depending on University to University.
There is a set rule for BS program that Philippines Universities should complete Prescribed total Study Units (Minimum 72 Units as per CHED) which takes 10 to 18 Months. Some Universities do more than 72-74 Study Units, which may be not be relevant. For example, In BS History of Philippines not required, in some university this is added in their BS Study Curriculum.