Green poop can be caused by several common and generally harmless reasons, most notably from eating large amounts of green leafy vegetables such as spinach, kale, or broccoli, because these contain chlorophyll, the green pigment in plants. It can also happen after consuming foods with green or blue food coloring like frosting, candies, or drinks. Other causes include bile pigment effects: bile is naturally greenish-yellow, and if food moves too quickly through the intestines (such as with diarrhea), bile does not have time to fully break down and can color the stool green. This faster transit can also be caused by infections (like Salmonella, E. coli, or norovirus), certain medications (including antibiotics, iron supplements, and antacids), or medical conditions affecting digestion. In sum, green stool is often diet- related but can sometimes signal faster gut transit or infections. If green poop is accompanied by other symptoms like stomach pain, diarrhea, fever, or vomiting, it’s a good idea to consult a doctor.