"After I went to the bathroom today I was surprised to discover my stool (poop) was green! What can cause my poop to turn green? Should I be worried? Should I call my doctor?"
Don't panic if you have the occasional green stool. In most cases, there is a perfectly good reason for the unusual green color, and your stool would still be considered in the range of a normal stool. To explain the green, think back to the foods you ate or any vitamins or supplements you took over the last several days -- even if those things are not green in color.
Why Stool May Be Green
There can be many reasons that stool appears to be green. The first and most obvious reason for a stool to be green is from eating green foods. Green, leafy vegetables contain chlorophyll, which could be coloring the stool green. Foods with dark purple coloring, such as Kool-Aid, popsicles, and gelatin (Jell-O), can also result in rainbow-colored stools. Iron supplements or even those foods that are rich in iron also have the potential to give stool a green tinge.
Is Green Stool Dangerous?
Stool can also appear green for physical reasons, and not just from what you've been eating. We think of a healthy stool as being brown. However, bile that is secreted in the first part of the small intestine is actually green. As stool is digested and passed through the large intestine it changes into a darker brown color.
If stool is still green by the time it is excreted from the body, it could mean that it went through the large intestine too fast to be changed to brown. This is often called "rapid transit" or "decreased colonic transit time," and diarrhea that is green in color could be the result.
Green Stools In Infants
In breast-fed infants, green stool is a normal occurrence, especially in the first days after delivery. In older children, the reason could be food-related as described above, or even from non-food items. Eating or sucking on colored non-food items, such as crayons, might also turn stools a different color.
If green stool continues, or your bowel habits have changed in other ways, you may want to call your doctor. This is especially true if you are experiencing diarrhea, which can be an indication of other problems or could lead to dehydration.