Stomach flu, vomiting and diarrhea all thursday night. drank lots of water, vomited more of course, but noticed green bits like mucus or chives in it?

Green stuff??: Could have been dietary related or could have been some bile which you up chucked.

Nothing serious: The color of vomit or diarrhea, or the appearance of bits and chunks of various sorts (mostly partly digested food), says nothing about the cause or severity of the problem. The main exception is that obvious blood is a concern. Otherwise, don't worry about it. Most viral gastroenteritis ("flu" is a misnomer) is caused by norovirus and is most severe for 24-48 hr, then should improve. Good luck!

See a doctor: If you keep vomiting or you could not hydrate yourself go to urgent care or the closest ER. Otherwise drink Gatorade and juices and water, eat yogurt and banana, have saltines crackers, and ginger ale, or Sprite . Check health tap check list on diarrhea and vomiting