Bile Vomiting – Causes of Yellow to Green Fluid

Vomiting up green to yellow liquid can be a cause for concern at times. We usually expect to see partially digested and some undigested food mixed with water and digestive juices. We often think that vomitus is the contents of the stomach but even some of the intestinal contents may be expelled when vomiting. Bile can also be vomited out and usually appears as a yellowish-green fluid.

Why does bile come out in vomit?

Waste substances filtered and produced by the liver are dumped into the digestive tract where it can be expelled by stool. These substances as well as unneeded nutrients are secreted as bile by the liver. Bile is stored in the gallbladder and is then pushed out into the duodenum of the small intestine where it mixes with food until it can pass out with stool.

The duodenum connects to the stomach. When the strong contractions occur that causes vomiting, the gallbladder may be squeezed and propelled from the duodenum into the stomach, up the esophagus and into the mouth where it passed out as vomitus. Therefore bile vomiting may just be a consequence of very intense and violent vomiting.

Bile not only carries wastes out of the body but it also has the additional function of breaking down (emulsifying) fats. In fact bile is secreted from the gallbladder in response to fats in the digestive tract. Therefore a person who consumes fatty meals when suffering with a condition that is causing recurrent and severe vomiting may find that bile is eventually expelled.

Causes of Bile Vomiting

There are several conditions where bile vomit may seen. It is usually associated with digestive conditions where vomiting is severe. However, bile vomiting can also occur with certain medication, ingested substances and eating disorders. In fact any condition that presents with vomiting may lead to the vomiting of bile as well.

Sometimes an offensive smell, disturbing visual image or even strong emotion like intense fear can cause vomiting. It may be repeated and violent to the point that bile may be passed out in the vomit. Yellow to green vomitus is not always bile. Eating foods or drinking beverages with a very strong yellow to green color and then vomiting afterwards can sometimes be mistaken for bile vomiting.

Gastroenteritis and food poisoning

This is one of the more common causes of sudden and severe poisoning. It arises when viruses or bacteria, or its toxins, irritate the stomach and intestines. Nausea, vomiting, diarrhea and abdominal cramps are the main symptoms. Most cases of gastroenteritis are due to viruses and is therefore commonly referred to as the stomach flu. With food poisoning, the microbe or toxin is consumed in contaminated food or water.

Excessive alcohol consumption

Every person has an individual tolerance for alcohol and it usually increases with repeated drinking. However, there is a point where a person may consume an excessive amount of alcohol and this can lead to alcohol poisoning. Even without alcohol poisoning, excessive alcohol intake may lead to vomiting as it irritates the stomach and intestines. The body may therefore try to expel whatever alcohol is remaining in the gut by the process of vomiting.


A number of drugs can cause vomiting as a side effect. These drugs may reach the chemoreceptor trigger zone (CTZ) in the brain through the blood stream. The CTZ then stimulates the vomit center and initiates vomiting although there is no actual irritation of the digestive tract. It is frequently seen with cancer drugs (chemotherapy) but may also occur with other medication.

Intestinal obstruction

Any blockage of the intestines can cause food and fluids to back up. It eventually leads to abnormal distension of the bowels and stomach which can initiate the vomiting process. Intestinal obstruction may occur with tumors, strictures, foreign bodies, swelling due to inflammation, gallstones (ileus), adhesions (following surgery), twisting of the intestines and birth defects (congenital) in babies. Abdominal pain, distension, constipation and vomiting are some of the symptoms present.


After a cholecystectomy (gallbladder removal surgery), many people suffer with bile reflux. The bile enters the stomach or esophagus and causes inflammation of these organs. If there is any other cause of vomiting, the bile in the stomach or esophagus may then be expelled as vomitus. Bile reflux can also occur with any other surgery that may affect the pyloric sphincter. This is the end portion of the stomach that usually prevents backward flow of intestinal contents into the stomach.

Cyclic vomiting syndrome

This is a chronic disorder of unknown origin where a person may experience hours or even days of nausea and repeated vomiting. The condition may then resolve on its own only to recur days, weeks or months later. The vomiting can be so severe that bile may be passed out in the vomitus. Bile vomiting usually arises once the stomach is emptied of all its contents.

Eating disorders

People suffering with bulimia tend to purge after eating a meal. They may stick a finger or toothbrush down the throat to expel the food that they just ate. Since bile is secreted in response to food in the gut, especially fatty or oily foods, it is not uncommon for a bulimic to eventually find bile in the vomit. This may not always occur with the first or second vomit but repeated purging will eventually lead to bile vomitus.

Food intolerances and allergies

Food intolerances arise when the body is not able to digest certain foods, often due to a lack of certain digestive enzymes. One of the common food intolerances is lactose intolerance where the body cannot digest milk sugars (lactose) due to the deficiency of the enzyme lactase. The undigested food can then irritate the stomach and intestines and trigger vomiting.

Food allergies are where a person is sensitive to certain foods. When these foods are consumed the immune system abnormally reacts to its presence. It causes inflammation of the gut and this can the lead to vomiting. The vomiting may be recurrent until the trigger food (allergen) is expelled and the inflammation of the gut subsides.

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