every pregnancy is different but at 36 weeks you are getting close! I had diarrhea after my water broke so it was clear my body was 'cleansing' itself. Sorry, there is no straight answer to your symptoms. Definitely ask your ob. Good luck to you and congratulations!
I started throwing up again about two weeks before my daughter was born but I didn't have diarrhea. So its a possibility every pregnancy is different though.