Why Is My Stool Green? 7 Common Causes

TL;DR: Green stool is usually harmless and can result from diet or mild digestive changes. However, persistent or severe symptoms warrant medical evaluation to rule out infections or underlying health issues.

Overview

Wondering why is my stool green? Green stool can be surprising and sometimes concerning, but it’s often caused by common, non-serious factors. Your stool color reflects how quickly food moves through your digestive tract and what you consume. In this post, we’ll explore 7 common causes of green stool and help you understand when to seek medical advice.

Key Causes

1. Rapid Transit Through the Intestines

When stool passes too quickly through the intestines, bile—the greenish fluid that aids digestion—doesn’t have enough time to break down completely, resulting in green stool. This often happens with diarrhea or gastrointestinal upset.

2. Diet Rich in Green Vegetables

Eating large amounts of green leafy vegetables like spinach, kale, or broccoli can tint your stool green due to the natural chlorophyll content.

3. Artificial Food Colorings

Certain foods and drinks, including candies, ice creams, or drinks with green, blue, or purple dyes, may cause green stool. Pay attention to recent dietary changes if you notice this color shift.

4. Iron Supplements

Taking iron supplements or multivitamins with iron can sometimes cause greenish or dark stools as a side effect. Consult your healthcare provider if you’re unsure.

5. Antibiotics and Medications

Some antibiotics and medications alter gut bacteria and digestion speed, potentially leading to green stool. Always read medication side effects and inform your doctor about any new symptoms.

6. Infections

Certain bacterial infections (like Salmonella or Giardia) speed up intestinal transit or disrupt the gut environment, causing green diarrhea. If accompanied by fever or abdominal pain, seek medical care.

7. Medical Conditions

Less commonly, green stool may signal conditions such as Crohn’s disease, irritable bowel syndrome (IBS), or bile acid malabsorption. Persistent changes in stool color, frequency, or consistency should prompt evaluation.

When to Seek Help

If you experience green stool along with any of these warning signs, consult a healthcare professional:

  • Persistent diarrhea or stool color changes lasting more than a few days
  • Severe abdominal pain or cramping
  • Fever, chills, or signs of infection
  • Blood or mucus in your stool
  • Unexplained weight loss or fatigue

Timely diagnosis is essential to address any potential underlying health concerns.

Try It Yourself

Curious about your stool color? Try our free poo colour decoder! Quickly identify what your stool color might be telling you about your digestive health and when to seek medical advice.