Why is My Poop Green?

2. Caffeine, Alcohol, and Spicy Foods Cause Green Stools

Bile helps the human body with fat digestion. During the digestive process, the bile is released into the small intestine from the bile ducts. From there it moves, along with digested food, into the large intestine. As the bacteria in the large intestine interact with the bile, the stool changes color from green to yellow to brown. However, large amounts of caffeine, alcohol, or spicy foods such as jalapeno peppers can cause a laxative-like effect on the digestive system. Before the stool changes from green to brown, the body passes it through, and the stool is green.