Why Is My Stool Green in Color?

Green stool color may be caused by eating too many green vegetables, indigestion, biliary diseases, and other reasons. Healthy stool is brownish yellow, and sometimes due to different foods consumed, there may be some differences in the shape and color of stool among normal individuals. Eating pork blood or animal viscera can turn stool reddish brown, while eating a large amount of green vegetables with high chlorophyll content can make stool appear green. Green stool may indicate indigestion, and if green stool is mixed with pus, it may indicate acute enteritis or bacillary dysentery. In patients who have undergone major abdominal surgery or received extensive antibiotic treatment, a sudden occurrence of green watery stool with a fishy odor and grayish white translucent egg white-like pseudomembranes may suggest Staphylococcus aureus enteritis. Biliary diseases such as gallbladder polyps, gallstones, and cholecystitis may lead to abnormal bile secretion in patients, and excessive bile is excreted through the body's excretory system. As bile oxidizes, it turns green, which can cause green stool color. Patients may also experience symptoms such as right upper abdominal pain, abnormal weight loss, and loss of appetite.

Normal individuals usually have 1-2 bowel movements per day, averaging 150-200g of stool. The amount of stool is related to the types and quantities of food consumed as well as the functional status of the digestive organs. Individuals who consume a diet high in meat protein typically produce less stool than those who follow a vegetarian diet. In cases of indigestion, due to incomplete digestion and absorption of food, large amounts of fat droplets, starch granules, or incompletely digested muscle fibers may be visible in the stool, leading to increased quantity and frequency of bowel movements. The color of healthy stool is closely related to changes in health status. Normal stool is formed and soft. When indigestion or acute enteritis occurs, bowel movements may increase due to faster intestinal motility and less water absorption. In cases of constipation, stool may become dry and lumpy due to prolonged retention in the intestines, resulting in the absorption of water. When there is narrowing of the rectum or anus or partial intestinal obstruction, stool may often appear flattened or banded.