What causes an adult to have dark green bowl movements when I went to the bathroom today I noticed that my bowl movement was dark green, also had no smell..

Good . Good news! the only stool colors we get really concerned about are red (blood from colon), black (blood from small intestine or stomach), or white (liver is not working well). Colors such as brown, yellow, orange, green, even blue (blue kool-aid or blueberries) or purple (beets) can all be normal and usually associated with diet. If you have a persistent change in your stool habits, you should contact your physician since this could be a sign of an underlying disorder, but a one-time strange stool that is not red, black or white is usually of no concern.