Many people who would otherwise have “normal” bowel movements may discover, to their surprise, their stool has suddenly turned green. This may occur on a one-time basis while some people experience ongoing discoloration. Because many unusual colors of stool (particularly black, maroon, red or bloody) can often indicate some digestive problem, having green stool may throw some people into an unnecessary panic.
However, in most cases, you don’t need to panic if you have discolored or green stool. While strangely colored waste can be a sign of something weird going on in your system, it’s usually related to diet. Various foods, beverages, health supplements, and medications can cause bowel movements to vary in hue.
Dietary Causes of Green Stool
Do eating tons of green foods make the bowel movement come out green? Not necessarily, but that is certainly one possible explanation for green stool. Green food, particularly green, leafy vegetables (such as broccoli, spinach, and romaine lettuce) contain chlorophyll — the pigment that reflects light from leaves along the green wavelengths of the spectrum. It should be noted, however, you will not likely experience green bowel movements unless you consume these foods in excess.
Other foods that can cause green-colored bowel movements include:
- Green peas
- Green beans
- Green peppers
- Algae (or algae-based supplements)
Processed treats with food coloring can also color waste:
- Powdered drink mixes
- Lime sports drinks
- Candy (such as gummy-snacks, sour flavored balls, and suckers)
- Green-tinted ketchup or other condiments
If you take iron supplements, a multivitamin with a high concentration of iron, prenatal vitamins with iron or even follow a high iron diet, these factors could also explain the presence of green stool. If normal amounts of iron can’t cause green colored waste, why would excess iron create this effect? The body is not able to properly absorb large quantities of iron, so it compensates by excreting iron salts that can cause stool to appear greenish.
If you’re not consuming anything that might be the reason for green stool, something physiological may be occurring within your digestive system.
For example, healthy, normal stool is generally a brown color. Food first enters the small intestine where it is broken down by bile secreted from the liver. This bile is bright green in color. At this stage, vitamins and minerals are absorbed and the waste product is transferred on. However, only after all the food is digested does it turn from green to yellow to brown. This shift in tone is caused by beneficial bacteria and other components of the digestive system.
Even though stool is supposed to change from green to brown, this does not always happen. If your bowel movement is still green at the time of elimination, it might be because your food wasn’t digested properly and it moved through too quickly. In other words, the enzymes didn’t have a chance to break it down, thus leaving you with green stool.
If you produce green diarrhea, this is the likely explanation. The waste is passed on when it’s still in a liquid form, either from an intestinal virus or due to some anomaly in the digestive process. This phenomenon is also known as “decreased colonic transfer time,” or “rapid transit.” If you continue to experience green diarrhea, you may want to consult your doctor for treatment options for the diarrhea, as it could lead to dehydration or other problems if ignored.
Additional Causes of Discolored Waste
Green-tinged stool can also occur in infants that are breastfed, but it’s normal in this context. Older children could experience green stool from green or dark purple-colored foods, or even from sucking on or chewing inedible objects with dyes such as crayons. Discolored stool can also occur as a side effect of prolonged use of laxatives, antibiotics, or other prescribed medication.
However, even though the occurrence of green waste is generally a benign issue, underlying conditions such as digestive diseases may be at work.
Biological reasons for green waste include:
If you suddenly have green stool, or you’ve been experiencing recurrently green stool, it’s best to consult a qualified doctor. It’s always important to note any abrupt changes in your bowel movements so you can determine the best course of action together. Although the green stool may be related to your diet or health supplementation, or an illness, it’s wise to check for serious digestive issues as a precaution. Of course, the sooner these problems are discovered, the more likely you are to receive successful treatment.