Causes of Green Stool

Stool comes with different colors (brown, green, red, yellow, orange etc.) with brown as the considered normal color. People are curious and even alarmed if they saw that their stool is not brown. For example, people who have bright red blood in their stool fear that they may have rectal bleeding and other gastrointestinal diseases. Some people are also alarmed (or just curious) if they saw that their poop is green. However, having a green stool should not be a cause of fear because it is not an uncommon condition. People regularly excrete green stool depending on the passage of bile in their intestines and the food they are eating. Continue reading to learn the causes of green stool.


Bile, a bright green fluid, is constantly secreted by the liver towards the small intestine or temporarily stored in the gallbladder. Bile is needed for the digestion of lipids in the small intestine. It also makes the stool soft and gives stool its characteristic color.

Bile changes color from green to brown as it travels down from the small intestine to the large intestine .The color change is due to bacterial actions in the large intestine. Bile mixed with undigested food travels slowly in the large intestine giving bacteria enough time to act on bile. Bacteria then perform chemical changes to bile changing its green color to brown. However, if stool travels in the large intestine faster than normal, bile cannot be transformed chemically retaining its green color. If a person has a diarrhea, his poop could be green because it traveled so fast in the intestines.

Another cause of green stool is eating green foods such as algae, lettuce, spinach, broccoli, kale, Swiss chard, and among others. These leafy vegetables contain the green pigment chlorophyll that can turn the color of stool to green. Eating foods with green food coloring can also make stool green.

Taking iron supplements or eating foods high in iron could also cause green stool.

If you cannot think of any reason why your stool is green, you are always free to consult your doctor.[ad#afterpost]