The liver constantly secretes a bright green fluid called bile into the small intestine or it is stored in the gallbladder.
Bile is needed to absorb fats and fat soluble vitamins. It also helps to soften stools and is responsible for giving stools their characteristic brown color.
As bile makes its way through the intestines, it progressively changes color from green to yellow to brown, due to the action of bacteria in the large intestine on the bile salts.
Green stool often indicates that food has passed through the intestines faster than normal (called decreased bowel transit time), before it could be changed from green to brown.
Diarrhea decreases bowel transit time, so any condition that causes diarrhea can result in green stool.
Other causes of green stool include:
- Laxative use
- Antibiotic use
- Medication side effects
- Food poisoning
- Celiac disease
- Ulcerative colitis
- Crohn's disease
- Malabsorption
- Irritable bowel syndrome
- Bacterial overgrowth
- Infectious diarrhea - especially salmonella and giardia
- Traveler's diarrhea
- Cancer
Foods and supplements that can cause green stool include:
Note: Speak with your doctor about any change in bowel movements.
