Been on one day of liquids for colonoscopy, starting second day. haven't taken laxatives yet but noticed last formed stool was green. why might this be? should i inform doctor/emergency? deeper green color.

No big deal: Green stool is no problem. May be related to what you ate or drank. Go take your laxative at the time, you are supposed to take.Good luck for colonoscopy

Not concerning.: Stool color can vary because of a lot of factors, most notably diet. It is generally not a concern unless the store is bloody or solid black in color, due to bleeding, and will eventually return to normal. Green stool is not usually a concern. Be sure to drink all of your prep. Good luck.