Green Diarrhea-Dark, Bright, Watery, Lime, Causes, Meaning and what to do

What causes dark, bright, lime and water Green Diarrhea in children, adults, infants and toddlers? what do these shades of green in your stool mean or imply? How do you stop, prevent or cure diarrhea fast. Read to discover a lot more about green stool

What does green diarrhea mean?

The normal color of stool whether solid or diarrhea is brown but unfortunately, diarrhea may manifest in different colors that may be shocking and squirty. Urine and stool appearance is a biological window to your body. It is therefore upon you to keep a close eye on any changes in color.

The stool has a green tint and this may be normal or abnormal based on symptomatology. Green diarrhea, in shades of dark, bright or lime may imply a couple of conditions both mild and severe.

Green stool may indicate what you’ve just eaten. For example, if your diet is full of green leafy vegetables then expect green that comes from chlorophyll in the green plants.
It may also indicate that your using green food coloring in your cooking recipes.

It may also indicate certain drugs and medication, an underlying infection and a breach in the physiology of your digestive system.

Why is My Diarrhea Green? Causes Adults & Toddlers

Causes in adults

Iron rich foods and supplements

Iron-deficiency is the most common form of nutritional deficiency in expectant mothers and children. This type of nutritional deficiency may have lethal implications on the integrity of the immune system, growth and development of a baby and hematopoiesis (synthesis of red blood cells).

As such, the side effect of prolonged intake of iron supplements by children and pregnant mothers, is not uncommon. Iron in its reduced state is green in color and the presence of reduced iron in the stool results in a green color. The iron ions in the digestive system shifts the electrolyte imbalance in the lumen and results in an osmotic pull of water into the lumen. Diarrhea is a consequence of this osmosis.

Medical Conditions

  1. Salmonella infectionsalmonella occurs as a form of food poisoning originating from uncooked of partially cooked food. Salmonella is predominantly harbored by poultry such as chicken and its products therefore. Eggs, consumed raw, may result in salmonella infections in about 0.001% of the eggs. The probability becomes higher with low quality eggs and in hens that have not been tested for this bacteria. Apart from the excessive vomiting and muscle pains, salmonella-caused diarrhea is mild greenish. Chicken should therefore be thoroughly cooked and checked for the normal white color while cooking and not red due to bleeding when pricked.
  2. Giardia lamblia intestinalis infectionGiardia is contracted by eating infested meat or drinking unclean water.Acute diarrheal illness from Giardiasis occurs with profuse, watery kind of diarrhea that later complicates to malodorous and greasy diarrhea. The color of the stool ranges from yellow to green. Giardia normally relies on B vitamins, bile salts and glucose for its survival. Therefore, the dependence of Giardia on the taurin and glycine salts of bile acids may result in reduction of both glycine and taurin. Free bile acid concentration increases and when secreted into the intestines, results in the green color. An increase in bile salts in the colon causes bile acid diarrhea.
  3. Postnasal drip – the digestive and respiratory system produces 1-2 quirts of mucus per day. The mucus produced in the throat and nose may drip at the back of the nasal pharynx and mixes with saliva. The saliva is then swallowed. Note that postnasal drip may be caused by infections. The infectious pathogens may result in yellow to green color – Elle McKinley[i]
  4. Gastroenteritis(Stomach flu) – this is an inflammation of the digestive tract that may be caused by either a bacterial or a viral infection. The inflammation of the intestinal wall may result in malabsorption of bile salts and this results in green color in the stool. In the colon, secondary formation of bile salts may result from bacterial infections.
  5. Intestinal disorders – such as Crohn’s disease and Irritable Bowel Syndrome. These two diseases bear a defect in the integrity of the intestinal epithelium and as a result, the bile salts are not efficiently reabsorbed.
  6. Celiac disease – this is simply an allergy to gliadin found in gluten in wheat, rye or oat. The abnormal reaction to this protein results in destruction of the intestinal wall. Therefore, a malabsorption of bile salts.

Drug Side-Effects

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.

Antibiotics may kill off some of the bacteria that naturally grow in the digestive system which can cause the stool to turn green as it is expelled. This side effect should become limited or will be eliminated all-together as your body becomes used to the medication, or once you stop using your medication.

Laxative medications cause digested food to move fast through the system and hence there is sub-optimal digestion and absorption. There needs to be ample time for bile salts to act on the food after which, they are degraded into biliverdin and bilirubin. These two are responsible for the brown color.

However, bile still retains its character and therefore the green color in stool. Other medication include internal deodorants; chloresium, derifil, chlorophyll. Antibiotics may clear the normal flora in the gut and may also be responsible for a green tint as the bacteria are expelled.

Drug can cause green diarrhea in adults

Increased consumption of chlorophyll

The amount of chlorophyll consumed in leafy vegetables such as broccoli may result in dark or light green color in the stool. Controlling the amount consumed can be controlled upon sight of green stool.

Alcohol and Green Diarrhea-

Why do you get diarrhea after drinking alcohol? Can excess or too much beer, wine cause loose. Alcohol is one of the substances known to irritate your digestive system.

Even small amounts of alcohol can make your stomach produce more acid than usual, which can in turn cause an inflammation of the stomach lining. This in addition to diarrhea, triggers stomach pain, vomiting. Heavy drinkers may experience bleeding. That is it. Alcohol in excess, especially beer and wine, may cause loose stools the next day.

Causes infants, toddlers and children

Stool color is an important indicator of what has been ingested or what is happening in the body of a child. This comes in handy as they can find anything edible. It is therefore pertinent to continuously check the fecal appearance and the frequency of defecation in them.

The occurrence of green stool may be of minimal implication other than regulating the dietary intake. It may also be an indicator of a more serious condition. It is worthwhile to not that in infants, the stool color may resemble that of the food that was ingested.

The stool of a newborn is usually runny. Therefore to determine that there is diarrhea, the frequency, volume, smell and physical appearance are scrutinized. Exclusively breastfed newborns poop after every meal. This may sum up to around 6-10 times in a day. This frequency slows down with growth and maturity. Here are the common causes of green poop in infants.

  • Meconium

This is the first poop of a newborn. It is expected to occur within the first 48 hours. You should expect a green-black stool (dark green). It is also tarry and sticky. It is composed of mucus, amniotic fluid, mucus and other substances that were ingested in utero.

  • Transitional stool of the newborn

You should expect this within the 2nd and 7th day. The stool is still runny but light green in color. This is a good indicator of the normal functioning of the digestive system.

  • Exclusive breastfeeding of a healthy baby

So long as the baby has been examined by your physician and has been found to be healthy, green stool at this point is okay. The shades of green during breastfeeding changes with foremilk to hind milk ratio. The color ranges from dark to light green. Without any other symptoms, this is healthy.

  • Excessive foremilk

If your baby is suckling on too much foremilk, according to[2] and too little hind milk then green stool is not surprising. The milk babies suckles on is produced from the alveoli in the breast.

The milk produced has traces of cholesterol that however get trapped along the ducts. The lighter milk component with less cholesterol is therefore the closest to the ducts and hence termed ‘foremilk’.

The remaining has a high cholesterol content and this is the hind milk. The foremilk has a higher amount of lactose and breastfeeding of it too much will cause diarrhea and symptoms of typical lactose intolerance.

It also does not lead to satiety and the baby craves for more and this becomes a vicious cycle. If the bile produced does not meet the cholesterol, it is defecated together with the stool and gives it the light green color.

Feeding on one side per feeding or per couple of feedings will be beneficial. Pumping off some foremilk or unlatching once lactation has been triggered will also help.

  • Feeding your baby on healthy formula

This leads to a variety of colors ranging from brown, yellow to green. The stool is also more malodorous that of a baby consuming solid food. The iron in the baby formula may not be properly absorbed.

  • Iron supplements and medication

Iron fortifications may result in a green-black stool color that in combination is dark green. This arises due to the iron ions that when in their reduced state, are green while in the oxidized state, such as in melena (black stool due to digested blood), is black.

Increase in the speed of bowel activity as a result of use of laxatives can cause green stool. Medications like derifil and chloresium too. Indomethacin and some antibiotics have also been shown to cause green stool.

  • Partially digested food

With foods that are indigestible or partially digestible such as greens and carrots respectively, the color of the stool may be tinged with their color. The rate of the gastro-intestinal motility may be too high as to cause incomplete digestion of food. Chunks and color hues of the respective incompletely digested food may raise an alarm though this is not serious. With consistent presence of undigested food in the stool, consult a doctor.

  • Diarrhea

The fast transit of digested food may not allow enough time for bile emulsification and as a result, a bright green color may occur in the stool. Diarrhea may be caused by medications such as antibiotic induced diarrhea, bacterial toxins such as cholera toxin and an imbalance in the normal flora in the gut.

  • Abnormal bile secretion and absorption

If bile acid is secreted in excess, owing to its bright green color, it will tint the stool green. Normally bile has to emulsify the fat content in food and as such, changes its color with time to give stool a brown color. Bile salts are physiologically absorbed in the ileum through the entero-hepatic system back to the liver.

The transporters of bile through the gut wall are not present in the colon or jejunum. This means that a breach in the ileal wall causes a disruption in the entero-hepatic pathway. Bile acids accumulate without hope of absorption in the colon and hence its green color is observed in stool. The bile salts also cause hypertonicity in the lumen and watery stool thereafter.

  • Coli food poisoning

This is the most common cause of food poisoning in children. One of its signs is a dark to light green color of stool with abdominal cramping and pyresis (fever).

  • Gastro-intestinal diseases

These diseases are mainly those that result in the destruction of the ileal epithelium or ileum resection (surgical removal of a part of the ileum). Ulcerative colitis, irritable bowel syndrome, Crohn’s and celiac are a few.[3]

Dark Green Liquid/Watery Diarrhea

It is important to differentiate diarrhea and ‘just-watery’ stool. Watery stool may occur up to twice a day and this doesn’t necessarily mean it’s diarrhea. Diarrhea is a higher frequency of occurrence of higher than usual volume of watery stool not less than 6 times a day.

It occurs as the commonest sign of gastro-intestinal disease according to the Center for Disease Control. It also states that at least 2 million people world-wide, mostly children, die of consequences of diarrhea.

It may also be used as a marker of an underlying disease not necessarily in the intestines but secondarily affecting them.

dark  in babies & toddlers

  1. Meconium
  2. High amount of foremilk
  3. Laxative medications
  4. Iron supplements and fortifications
  5. Tylenol and indomethacin medications
  6. Broad spectrum antibiotics
  7. coli infection
  8. Medication and iron supplement


Dark green diarrhea in pregnant mothers

  1. Iron supplements
  2. Susceptibility to infections due to lowered immunity – mother’s immunity is reduced so that the immune cells do not attack the embryo.
  3. Diarrhea due to imbalance in normal gut flora
  4. Stress and tension increases the speed of digestion and may be diarrhea-causing

Dark Green Watery Diarrhea

What makes stool dark green watery and what is the implication?

Bile Secretion and transport process
  1. Increased bile salts in the gut lumen – bile salts result in an increased osmotic pull of water across the intestinal epithelium and increases water content.
  2. Increased lactose in the lumen – as observed in excessive consumption of foremilk, lactose is increased in the lumen. Lactose is an osmotically active substance. It therefore pulls water through osmosis into the lumen.
  3. Increase electrolyte content – the iron ions increase the electrolyte content in the lumen and increases the gradient of osmosis. Water is pulled in to the lumen.
  4. Bacterial toxins – bacteria such as salmonella and Giardiasis affect the biochemical pathways in the intestine. They therefore affect the movement of ions across cell membranes and a change in the osmotic gradient between the lumen and the intestinal epithelia.
  5. Exclusive breastfeeding in infant – if the only feeding the baby does is the mother’s milk, then the stool will be ever runny. This however changes with the introduction of solid food to the baby.
  6. Osmotic diarrheas (such as pancreatitis, sprue, bacterial overgrowth, and Whipple’s disease) are characterized by bulky, greasy, foul-smelling stools, weight loss, and improvement in diarrhea with fasting. This form of diarrhea results from an ingested solute that is not absorbed by the small intestine. The unabsorbed solute exerts an osmotic force and draws fluid into the intestinal lumen. The resultant increased stool volume exceeds the colon’s reabsorptive capacity,
    and diarrhea ensues. Stool analysis shows a gap between electrolyte concentrations and total stool osmolality due to the unabsorbed solute – Donelly and Dr. Giza, M. D[4]

Overall implications of watery stool in diarrhea include a variety of signs and symptoms that are linked to dehydration:

  1. Risks of low blood pressure – when much of the water is eliminated from the body, the cardiovascular system and interstitial compartment are deprived of water. This results in reduced blood pressure.
  2. Cerebral hypotension – when there is hypotension in the vascular system, the brain and the periphery do not receive enough pressure. This causes reduced blood pressure.
  3. Confusion – this results from hypoperfusion of the brain upon reduced blood pressure. The brain cells may become deficient of enough oxygen and nutrients. This reduces the brain’s function.
  4. Dizziness and vertigo – also results from hypoperfusion of the brain cells especially the area that is responsible for wakefulness and consciousness.
  5. Lethargy –general weakness and fatigue as a result of muscle weakness. The muscles become weak due to low blood perfusion of the muscle cells.
  6. Dry skin
  7. Constipation
  8. Electrolyte imbalance – diarrhea leads to loss of vital ions that are involved in the balance of the intracellular and extracellular fluid compartments.
  9. Anuria – reduced urine output and frequency
  10. Dark yellow, concentrated urine

Dark Green Diarrhea – Vomiting and Stomach Cramps Implication

Dark green diarrhea is less serious with dietary causes and when void of other symptoms such as vomiting and abdominal pains. This is an indication of a bacterial or viral infection. It may be an indication of E. coli infection.

Bright Green

Mother breastfeeding

Bright Green stool Causes and implications

The causes of bright green diarrhea arises due to the following reasons

  1. High amounts of bile acids produced from the gall bladder
  2. Below threshold absorption of bile acids through the entero-hepatic system
  3. In infants, bright green diarrhea occurs within the first week after the meconium. This transitional stool is bright green indicating that the gut is normal-functioning.
  4. High intake of broccoli
  5. High amount of foremilk than hind milk during breastfeeding.
  6. Coli bacterial infection

Also, bright green stool or poop is usually caused by lack of food. In most cases, when infants and toddlers are sick they don’t eat much.

Bright Green Diarrhea and Nausea without Vomiting

When a bright diarrhea is accompanied with nausea but no vomiting, these are the likely causes and implications some of which have been mentioned above.

  1. Gastritis-inflammation of the lining to the stomach
  2. Lactose Intolerance-Inability to digest sugar(lactose),  found in milk products
  3. Viral Gastroenteritis- inflammation of the stomach and intestines, as a result of a viral infection

Lime Green Diarrhea

The causes of lime green diarrhea are the similar to those of the bright green diarrhea. Different shades of green are evident in different cases. It is therefore not astonishing to get lime green color. This however is a chronic case of high levels of bile acids.

When should you worry about Green Stool?

You should be wary when the green stool is accompanied by any other symptom. The symptom may be an indication of a primary disease. These symptoms include:

Cocktail of other symptoms

  1. Malodorous stool
  2. Abdominal cramps
  3. Bloating/ flatulence
  4. Abrupt weight loss
  5. Changes in the consistency of the stool
  6. Mucus in the stool
  7. Greasy stool
  8. Blood spots in the stool
  9. Dizziness, lethargy and confusion

Persistence of:

  1. Stool color
  2. Malodorous stool
  3. Frequency of diarrhea

In case of occurrence of these symptoms, a doctor should be consulted

What to do to Stop/Prevent Green Diarrhea Fast

Diarrhea rush
  1. Take enough fluids and pay attention to dehydration – a child or anyone with diarrhea should focus on replacing the lost fluid and electrolytes. Symptoms of dehydration should be watched for. These include attention deficits, weakness, confusion, sunken eyes, dry mouth and constipation. You should take increased amounts of water and oral electrolytes.
  2. Reduction or cessation of high-chlorophyll foods and medication for three days – these include the broccoli you are taking, derifil and chloresium.
  3. Reduction in the quantity of dose of iron supplements and fortifications
  4. Intake of probiotics such as yoghurt three hours after taking your antibiotics – this will help in the balance of the gut flora and prevent diarrhea.
  5. Increasing the amount of hind milk your baby is suckling on – can be done by feeding the baby on one breast per feeding or per couple of feedings, latching and unlatching or draining the foremilk once it is triggered – Diana West, BA, IBCLC, co-author with Lisa Marasco of  ‘The Breastfeeding Mother’s Guide to Making More Milk’.
  6. For bacterial infections antibiotics against them should be taken on prescription.


  1. Consumption of fully cooked meat to avoid infections by Giardia and salmonella
  2. Avoid consumption of raw eggs in high quantities.
  3. Frequent consumption of probiotics to prevent diarrhea
  4. Take controlled amounts of green leafy vegetables
  5. Be careful to consume fresh foods and avoid overstayed foods to avoid food poisoning

Further reading

Sources and References                                                                                   

  1. [1]
  2. [2]
  3. [3]
  4. [4]    Differential Diagnosis and Mnemonics; Thomas J. Donnelly, MD; Christopher C. Giza, MD


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