By Kristina Herndon, RN 

 Medically reviewed by Keri Peterson, MD

Yellow or greenish-vomit is usually a sign that you are throwing up bile. Throwing up yellow bile could indicate a potentially serious medical concern like a hiatal hernia or intestinal blockage. It can also happen if you have stomach flu or food poisoning and continue to vomit after your stomach is empty.

Certain medications can also cause you to vomit bile by relaxing the muscles that separate the stomach from the small intestine, where bile is secreted. If this happens, bile can backflow into the stomach and cause your vomit to be yellow.

This article explains what bile is and the various reasons why you may be throwing up yellow bile. It also explains how the various conditions are diagnosed, treated, and prevented and when it is time to seek medical care.

What Is Bile and Why Is It Yellow?

Bile is a greenish-yellow liquid produced by the liver and stored in a tiny organ called the gallbladder. During digestion, bile is released into the small intestine to break down fats so that nutrients and other substances in fat can be absorbed in the walls of the intestines.1

Bile is essential to the breakdown and absorption of fat-soluble vitamins like vitamins A, D, E, and K. Bile also breaks down cholesterol and different types of acids, salt, and minerals in food.

Bile is composed mainly of water as well as fats (like cholesterol, lecithin, and fatty acids), bile acid, and a substance called bilirubin that gives bile its color. Bilirubin is naturally yellow but when exposed to air turns a more greenish tone.2

Causes of Throwing Up Yellow Bile

During vomiting, the muscular passageway that separates the stomach from the esophagus—known as the lower esophageal sphincter (LES)—will spontaneously open, propelling any contents out of the stomach.

Yellow vomit occurs when bile backflows from the small intestine into the stomach. There are many reasons why this might occur:

Bile Reflux

Bile reflux occurs when the muscular passageway between the stomach and small intestine—called the pyloric sphincter—malfunctions, allowing bile to seep into the stomach and then the esophagus.3

Bile reflux is similar to acid reflux in which stomach acids seep from the stomach into the esophagus because of a dysfunctional sphincter.

Bile reflux often develops after gallbladder surgery and other upper gastrointestinal surgeries (like a gastric bypass). A peptic ulcer can also damage the pyloric sphincter either directly (by causing tissue injury) or indirectly (by increasing stomach pressure which disrupts the valve).3

Other symptoms of bile reflux include diarrhea, heartburn, abdominal pain, and a foul taste in the mouth. Bile reflux can occur on its own but is common with acid reflux.3

Hiatal Hernia

A hiatal hernia occurs when part of the stomach protrudes up into the chest through a thin muscle called the diaphragm. The compression of the stomach can place pressure on all of the sphincters of the stomach, including the pyloric sphincter and LES.4

A hiatal hernia is more common in older adults and people with obesity. Upper abdominal surgery, trauma, and long-standing gastroesophageal reflux disease (GERD) can also compromise the diaphragm, increasing the risk of a hernia.5

A hiatal hernia can also cause heartburn, upset stomach, throat irritation, belching, and regurgitation.5

Intestinal Blockage

An intestinal blockage occurs when the intestines are either obstructed physically or damaged by disease. When either of these happens, bile can pool (rather than being excreted in stool) and eventually backflow into the stomach.6

An intestinal blockage can lead to symptoms like:6

• Severe abdominal pain and cramping

• Fullness and swelling of the abdomen

• Bloating

• Inability to pass gas

• Loud abdominal sound

• Vomiting

An intestinal blockage can be caused by fecal impaction (in which hardened stools become stuck) and intestinal stricture (the abnormal narrowing of the intestinal passageway).6

People with Crohn's disease, ulcerative colitis, and lupus are at especially high risk of intestinal blockage. Intestinal strictures and blockage are also common in people with colon cancer.6

Vomiting on an Empty Stomach

When you vomit on an empty stomach—due to a severe case of viral gastroenteritis (stomach flu) or Salmonella poisoning, for example—there is really nothing else to vomit but mucus, gastric acid, and bile.

This can lead to vomit that is greenish-yellow, sticky, and possibly tinged with blood (if tiny blood vessels in the esophagus rupture). Chest pain, sore throat, and a bitter mouth taste are also common.7

Certain Medications

Certain medications can relax the pylorus sphincter, causing bile to seep into the stomach.

The classes of drugs most commonly associated with this include:8

• Beta2 agonists used for asthma and COPD

• Calcium channel blockers used for high blood pressure

• Nitrates used to treat angina

• Xanthines used to treat gout

• Benzodiazepines used for anxiety and insomnia

Other Causes of Throwing Up Bile

Vomiting yellow bile can also be caused by binge drinking. Alcohol increases the rate at which the gallbladder empties itself. It also slows the muscle contractions (peristalsis) that move food through the intestines.9

This combination of events can promote the backflow of bile into the stomach, which then gets regurgitated if the person drinks to vomiting.

Morning sickness can also sometimes manifest with yellow vomit. Because people with morning sickness often have an empty stomach, when vomiting does occur, all that may come out is bile, fluids, stomach acid, and mucus.10

In general, anything that can promote acid reflux can promote bile reflux as well, including:11

• Smoking

• Being overweight or having obesity

• A stressful lifestyle

• Lying down or reclining after meals

• Eating immediately before sleep

When to Seek Medical Care

Vomiting yellow bile may be due to something serious or something that is not. As such, even if it's a once-off event, it is important to speak with a healthcare provider if the vomiting is severe or accompanied by other symptoms such as diarrhea, heartburn, or abdominal pain.

Irrespective of the cause of your vomiting, you need to see a healthcare provider if you or your child experience:12

• High fever

• Inability to keep down liquids or food while vomiting three or more times in a day

• Vomiting that does not stop for 24 hours (or for 12 hours for infants)

• Recurrent bouts of nausea or vomiting

• Nausea for more than two days

Diagnosing the Cause of Vomiting Yellow Bile

If you've vomited what appears to be yellow bile, your healthcare provider will want to run tests to investigate the most likely causes. This typically starts with a review of your medical history and a physical exam.

Based on the initial findings, your healthcare provider may order:

• Blood tests: These include liver function tests (LFTs) and amylase or lipase tests to look for inflammation of the gallbladder and/or liver.

• Upper endoscopy: This involves the insertion of a thin, flexible tube with a camera (endoscope) into your throat to view the esophagus, stomach, and valves of the stomach.

• Imaging tests: Computed tomography (CT) and magnetic resonance imaging (MRI) can check for hiatal hernia, intestinal obstruction, strictures, and other gastrointestinal problems.

• HIDA scan: A hepatobiliary iminodiacetic acid (HIDA) scan is an imaging test that tracks the flow of bile from the liver to the small intestine over the course of one to four hours.

• Esophageal manometry: This test, commonly used to diagnose hiatal hernia, involves the insertion tube with a tiny probe into your nose to measure the rhythmic muscle contractions of your esophagus as you swallow.

• Esophageal impedance: This is a hospital-based test in which a tube with a tiny probe is fed through the nose and into the esophagus to check whether any bile is detected within a 24-hour period.

How Is Throwing Up Yellow Bile Treated?

If you've vomited bile, your treatment plan will vary based on the underlying cause. This can range from supportive care if you have stomach flu (anti-nausea drugs and fluids) to surgery to repair a hiatal hernia or intestinal obstruction.

If you have chronic bile reflux, medications may be prescribed to either reduce the amount of bile that infiltrates the stomach or prevent injury caused by bile reflux.

These include:3

• Bile acid sequestrants: These medications bind to bile so they can be carried out of the body more easily in the stool.

• Ursodeoxycholic acid: This drug breaks down bile into compounds that are less harmful to tissues.

• Lioresal (baclofen): This is a muscle relaxant that can decrease pressure on the pyloric sphincter.

• Carafate (sucralfate): This is a type of antacid that coats and protects the lining of the stomach and esophagus.

• Prokinetic agents: This class of drugs, which includes agents like Motegrity (prucalopride), stimulates peristalsis to prevent the backflow of bile.

Can I Prevent Throwing Up Yellow Bile?

If you have been diagnosed with bile reflux, you would need to make changes to better manage symptoms and prevent further episodes.

This might include:11

• Eating smaller, snack-sized meals several times rather than three big meals

• Avoiding lying down or reclining immediately after meals

• Eating two to three hours before bedtime

• Placing several pillows under your back and head when lying down to prevent the backflow of bile

• Losing weight if you are overweight or have obesity

• Exploring stress-reduction techniques like deep breathing exercises, meditation, or yoga

• Quitting cigarettes

• Drinking plenty of water for hydration

What Do Different Bile Colors Mean?

Different vomit colors mean different things, and it can sometimes be hard to tell if your vomit is more yellow, green, orange, or some shade in between.

Orange vomit can also occur with food poisoning and stomach flu. The color is due to food that has been partially digested, making the bile less yellow or greenish.2

The color doesn't necessarily mean that it is "more" of a problem compared to yellow unless there are other symptoms such as severe stomach pain or the inability to pass gas.

On the other hand, if you recently ate something that was green, yellow, or orange (particularly artificially colored foods like orange popsicles or lime gelatin), it is possible that the color of your vomit is due to that.13

What Foods Cause A Lot of Bile?

Eating foods that are high in fat triggers the gallbladder to release more bile into the small intestine to break down the fats. This is especially true of saturated fats found in animal-derived foods.

Fats stimulate the production of a hormone called cholecystokinin which, in turn, stimulates the secretion of bile. Because saturated fats are harder to break down, more cholecystokinin is produced and more bile is produced.3

Foods that can significantly increase bile production include:

• Processed meats like lunch meats, hot dogs, sausage, and bacon

• Full-fat dairy, including whipping cream and sour cream

• Butter and margarine

• Mayonnaise

• Fried or breaded foods

• Baked goods, including pastries, cookies, and croissants

When Should I Seek Emergency Medical Attention?

Vomiting under any circumstance is considered a medical emergency if there are signs and symptoms like:14

• Vomiting for more than 24 hours

• Blood in your vomit

• Severe abdominal pain

• Severe headache and stiff neck

• Severe dehydration, such as sunken eyes, dark urine, rapid heartbeat, or fainting

• Any reason to think that the vomiting is from poisoning

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Sfara A, Dumitrascu DL. The management of hiatal hernia: an update on diagnosis and treatment. Med Pharm Rep. 2019;92(4):321-325. doi:10.15386/mpr-1323

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Manley S, Ding W. Role of farnesoid X receptor and bile acids in alcoholic liver disease. Acta Pharm Sin B. 2015 Mar;5(2):158–67. doi:10.1016/j.apsb.2014.12.011

Bustos M, Venkataramanan R, Caritis S. Nausea and vomiting of pregnancy-what’s new? Auton Neurosci. 2017 Jan;202:62–72. doi:10.1016/j.autneu.2016.05.002

Sifrim D. Management of bile reflux. Gastroenterol Hepatol (N Y). 2013 Mar;9(3):179–80.

MedlinePlus. When you have nausea and vomiting.

Silva MM, Reboredo FH, Lidon FC. Food colour additives: a synoptical overview on their chemical properties, applications in food products, and health side effects. Foods. 2022 Feb;11(3):379. doi:10.3390/foods11030379

MedlinePlus. Nausea and vomiting.

By Kristina Herndon, RN
Kristina Herndon, BSN, RN, CPN, has been working in healthcare since 2002. She specializes in pediatrics and disease and infection prevention.