Green poop can mean several things, most commonly related to diet or digestive processes:
- Dietary causes: Eating large amounts of leafy green vegetables like spinach, kale, or broccoli can turn stool green due to chlorophyll, the green pigment in plants. Artificial green or blue food coloring in candies, drinks, or frosting can also cause green stool. Consuming foods like matcha or blueberries may contribute as well
- Bile pigment and digestion speed: Bile, a greenish-yellow digestive fluid from the liver, normally changes color as it moves through the intestines. If food moves too quickly through the gut, such as with diarrhea, bile doesn't have time to break down fully, resulting in green stool. This can also happen after gallbladder removal or on a high-fat diet that increases bile production
- Medications and supplements: Iron supplements can darken stool to green or black. Some antacids, antibiotics, and antidiarrheal medications containing bismuth subsalicylate may cause green poop by altering gut bacteria or reacting with digestive chemicals
- Infections and health conditions: Green stool can sometimes indicate bacterial infections (like Salmonella or E. coli), viral infections (norovirus), or parasites (Giardia), which speed up intestinal transit. Certain digestive disorders such as Crohn’s disease, celiac disease, ulcerative colitis, or irritable bowel syndrome may also cause green stool, especially if accompanied by diarrhea or other symptoms
- When to worry: If green stool occurs with symptoms like abdominal pain, weight loss, bleeding, fever, or vomiting, or if it persists without an obvious dietary cause, medical evaluation is advised
In summary, green poop is often harmless and linked to diet or transient digestive changes, but persistent or symptomatic green stool warrants medical attention.
