Consuming iron supplements can have a similar effect on the body. It can either cause the stool to become green or very dark colored. Strong food colorings or enriched foods can cause the body to emit dark green stool.
http://www.md-health.com/Dark-Green-Stool.html
1 The symptoms associated with stool color changes, if any, are the symptoms of the underlying cause cause of the change, for example, foods, drinks, conditions, or illnesses such as. 2  diet (beets, diets rich in green vegetables, licorice), 3  gallbladder disease, 4  celiac disease, 5  ulcerative colitis, 6  Crohn's disease, 7  tumors,
http://www.medicinenet.com/stool_color_changes/article.htm
Medications: certain medications such as laxatives or antibiotics can cause the stool to turn a dark green color. Laxatives cause digested food to move through the system more quickly, causing nutrients to be absorbed less effectively.
http://www.md-health.com/Dark-Green-Stool.html
Green stool can occur due to a normal or benign condition and not be a cause for concern. For example, you may produce green stool after consuming certain iron-rich foods or iron supplements, leafy green vegetables, or products with green food coloring.
http://www.healthgrades.com/symptoms/green-stool--causes
Causes of Dark Green Stool. Excessive intake of leafy vegetables, iron or dyes: an excessive amount of leafy green vegetables in the diet can cause the stool to turn a dark green color. Spinach, lettuce, broccoli or even peas can cause discoloration in the stool.
http://www.md-health.com/Dark-Green-Stool.html
2. Dietary Causes. A child’s diet can also affect the color of their stool. Green vegetables, like broccoli and cabbage, or foods that are dyed with either green, blue or purple food coloring, such as ice cream, soda and some breakfast cereals can cause a child’s stool to appear green in color.
http://www.just-health.net/Green-Poop-Toddler.html
In most cases, stool color changes are not symptoms of disease. Changes in stool color may be due to: 1  Diarrhea may cause green or yellow stools. 2  Some foods (beets, Jell-O, licorice). 3  A few OTC and prescription medications. 4  Diseases affecting the liver, pancreas, and intestines.
http://www.medicinenet.com/stool_color_changes/article.htm
Green stool can also be a symptom of various intestinal disorders that interfere with the normal digestion process, such as Salmonella food poisoning. As food passes through the digestive system, a yellow-green fluid called bile that helps digest food changes color, resulting in a stool that is light to dark brown.
http://www.healthgrades.com/symptoms/green-stool--causes
This can be caused by an excessive amount of the natural bacterial colonies in your digestive system, or exposure to dangerous bacteria such as Salmonella. Irritable bowel syndrome (IBS) can cause the stool to become a dark green color during an attack. Ulcerative coliti s may cause a similar reaction.
http://www.md-health.com/Dark-Green-Stool.html
Disease-related causes of green stool. Green stool can be caused by the following diseases: Bacterial infection. Celiac disease (severe gluten intolerance that damages the small intestine). Eating disorder, such as binge eating and abusing laxatives. Giardia (protozoan infection).
http://www.healthgrades.com/symptoms/green-stool--causes
what causes greenish stools?
Certain medications such as laxatives or antibiotics can cause the stool to turn a dark green color.