2 nights ago, I also woke up at 3 in the morning and puked up about 1/4 of my oil & citrus mixture. Like you I fell asleep again and was okay in the morning. Never released any stones or sludge, but it took me 2 days to excrete all the oil.
Pretty strange; every flush is different, isn't it! Puking up that oil mixture was some of the worst sensations I have experienced in my life, and I mean it. It took about 20 minutes and I think I would rather have a tooth extraction without anesthesia than go thru that again:)