Green Vomit: What It Means & What to Do

Green vomit can be a symptom of several conditions, including bile reflux, bowel obstruction, prolonged fasting, food poisoning, the flu, or pregnancy.

Along with green vomit, other symptoms may arise depending on the cause, such as abdominal pain, headache, loss of appetite, bloating, and weight loss.

If you experience green vomit, it’s important to see a primary care provider or a gastroenterologist for an evaluation. Treatment may involve rest, medication, or, in some cases, surgery, depending on the underlying cause.

Main causes

The most common causes of green vomit include: 

1. Bile reflux

Bile reflux happens when the pyloric sphincter, which separates the stomach from the duodenum, doesn’t work properly. This allows bile to flow back into the stomach or esophagus, leading to symptoms such as green, bitter vomit, abdominal pain, and weight loss.

What to do: treatment is guided by a gastroenterologist and may include medications like ursodiol (ursodeoxycholic acid) and bile acid sequestrants. These drugs help regulate bile flow and bind to bile acids in the intestine, reducing the frequency and intensity of symptoms.

If symptoms don’t improve with medication, surgery may be recommended to redirect bile away from the stomach.

2. Bowel obstruction

Bowel obstruction occurs when stool can’t pass through the intestines due to a blockage. This condition can cause difficulty passing stool or gas, green and bitter vomit, abdominal bloating, loss of appetite, and stomach pain.

What to do: treatment must always be done at the hospital. Intravenous (IV) fluids are given to improve hydration and help move stool through the intestines.

The person should remain fasting, and in many cases, a nasogastric (NG) tube is inserted to remove excess gas and fluids. In severe cases, surgery may be needed to remove the blockage and restore the passage of stool.

3. Prolonged fasting

Prolonged fasting can cause green and bitter vomit when the stomach stays empty for long periods. This may happen after vomiting throughout the night or in people with morning sickness, who wake up with an empty stomach and vomit bile.

What to do: it’s important to see a gastroenterologist or primary care provider, especially if vomiting is accompanied by other symptoms.

Maintaining a balanced and healthy diet and staying hydrated by drinking plenty of fluids (preferably water, oral rehydration solutions (ORS), or electrolyte beverages) is also important to prevent dehydration.

4. Flu

Because of mucus buildup, green vomit can occur during flu episodes, especially in pregnant people, older adults, and children. These groups are more vulnerable because their immune systems are weaker, making them more prone to infections.

Other flu symptoms may include fever, cough, runny nose, headache, muscle pain, and sore throat.

What to do: mild flu cases in healthy individuals usually resolve within about two weeks without specific treatment.

In moderate or high-risk cases, a healthcare provider may recommend antiviral medications, such as oseltamivir or baloxavir, especially if started within 48 hours of symptom onset. Fever reducers, anti-inflammatories, and pain relievers such as acetaminophen or ibuprofen may also be used to relieve discomfort.

Some natural remedies, such as ginger syrup, guaco syrup, or beet syrup, may help relieve symptoms, but these should only be used as complementary measures and never replace medical treatment when prescribed.

5. Food poisoning

Food poisoning can occur after eating food contaminated with toxins, which may result from improper storage, expired ingredients, or poor food hygiene during preparation. Frequent vomiting episodes can leave the stomach empty, causing bile reflux and green vomit.

Other symptoms may include nausea, headache, diarrhea, weakness, and dehydration.

What to do: treatment involves drinking plenty of fluids (preferably oral rehydration solutions, water, or clear broths) to prevent dehydration. Eating light, low-fat foods also helps the body recover, eliminate toxins, and relieve symptoms.

6. Pregnancy

During pregnancy, some women may experience green and bitter vomit due to morning sickness or hyperemesis gravidarum, a condition that causes frequent vomiting. This leaves the stomach empty, allowing bile to flow back into it.

Other common pregnancy symptoms include breast tenderness, mood changes, and excessive sleepiness.

What to do: mild hyperemesis gravidarum can be managed by avoiding foods or activities that worsen vomiting, getting adequate rest, and maintaining good hydration.

Tips that may also help include sucking on lemon or orange popsicles, eating a plain cracker right after waking up, and avoiding strong smells.

Newborns and babies

In newborns and babies, green vomit may range from light to dark green and can be caused by intestinal obstruction due to conditions such as intestinal atresia, meconium plug syndrome, or Hirschsprung’s disease. This condition affects normal bowel movements and can also cause constipation and abdominal bloating.

Green vomit may also occur in babies and children when mucus is present, such as during flu or pneumonia.

Additionally, green vomit can appear in cases of necrotizing enterocolitis, a serious condition that mainly affects premature newborns. It causes intestinal inflammation and can lead to perforation, peritonitis, and sepsis. Other signs and symptoms include loss of appetite, lethargy, and abdominal tenderness.