It generally takes about a week for the doctor who performed the exam to receive the medical results which he/she then would notify CIC. I'm not sure if there is any timeline for how long CIC takes to review the results once submitted by the doctor.
But if they already have the passport, and the interview passed, and all that's left is this medical, then it sounds like you should be looking for your ECAS to indicate "Decision Made" soon. Good luck. But as stated, each application is unique and it is sometimes hard to say what a timeline will look like.