Bilious vomiting factsheet
Bilious vomiting is when a baby's vomit is a colour ranging from yellow to green. It is usually a sign of a twisted or blocked bowel, which is a medical emergency.
Underlying causes of vomiting
Key facts
- Vomiting is a symptom, not a disease or condition and may clear up on its own.
- Vomiting can be classed as acute (short-term) or chronic (ongoing or recurrent).
- Gastroenteritis and food poisoning are the most common causes of sudden vomiting.
- Vomiting can also be a symptom of something serious.
- See your doctor if you have been vomiting for more than a few days, or if you are dehydrated.
What is vomiting?
Vomiting is a symptom, not a condition. It's a reflex that helps your body get rid of harmful substances. When you vomit, your abdominal muscles have strong contractions pushing out the contents of your stomach.
Seek immediate medical attention if you are vomiting and:
- have a fever (high temperature)
- have signs of dehydration
- can't keep water down
Vomiting may be a short-term or long-term problem.
There are many different reasons that you could be vomiting. The most common cause of acute (short-term) vomiting is viral gastroenteritis (gastro, stomach bug or stomach flu).
If you have recurrent or chronic (long-term) vomiting that continues for more than 2 days, see your doctor.
For information on the underlying causes of vomiting in children 12 years and under, see vomiting in children.
What causes acute vomiting?
Acute (short-term) vomiting may be caused by an infection, a medical treatment, poisoning, or some other reason.
Gastroenteritis
An infection of the digestive tract is one of the most common causes of nausea and sudden vomiting.
Gastroenteritis is often caused by a virus, such as norovirus or rotavirus.
Bacteria such as Salmonella, Shigella or Campylobacter, can also cause gastroenteritis. These bacteria are associated with 'food poisoning'.
Diarrhoea and abdominal pain often happen along with vomiting.
Food poisoning
Some bacteria can cause food poisoning due to toxins (poisons) that they release into food.
Bacillus cereus and staphylococcus aureus are examples of bacteria that can cause food poisoning. Symptoms of vomiting can start soon after eating the contaminated food.
Poisoning
Many household items are poisonous if swallowed. Symptoms of poisoning include:
- nausea and vomiting
- drowsiness
- seizures
- breathing difficulties
Warning:
Do NOT attempt to make yourself vomit, unless told to do so by a doctor.
Motion sickness
Motion sickness can cause vomiting in adults. You may also go pale and have cold sweats.
Too much alcohol
Drinking too much alcohol can often cause nausea and vomiting, or even alcohol poisoning.
After surgery
If you have just had surgery, you are likely to feel nauseous or vomit. You might be given anti-emetic medicines to stop you vomiting.
Gastrointestinal obstruction
An obstruction in your digestive tract will cause vomiting. It often begins without nausea.
Depending on where the blockage is, you may vomit:
- bile
- faecal material
- partly digested food
Seek urgent medical help if you have symptoms of bowel obstruction.
Appendicitis
Warning:
Appendicitis can cause both nausea and vomiting. Appendicitis usually causes a dull pain that starts around the navel (belly button). Pain might travel to the lower right of the abdomen and start to feel sharp. Other symptoms of appendicitis are a loss of appetite, fever or chills.
If appendicitis is not treated your appendix can become swollen and infected. It can even burst. Urgent surgery is the usual treatment for appendicitis.
Pancreatitis
Pancreatitis is inflammation of your pancreas. It usually causes:
- abdominal pain
- vomiting
- fever
It can be very severe, even life-threatening.
Raised intracranial pressure
Raised pressure in your skull is a medical emergency and can cause nausea and vomiting.
It might be due to:
- a head injury
- meningitis
- a tumour
Your vomiting may be worse in the morning and may be projectile.
Meningitis
Warning:
Symptoms of meningitis can happen suddenly, and include:
- vomiting
- fever
- headache
- a stiff neck
- photophobia (light sensitivity)
- a distinctive rash
COVID-19
Nausea, diarrhoea and vomiting can all be symptoms of COVID-19.
Diabetic ketoacidosis
If you have diabetes, vomiting can be a symptom of diabetic ketoacidosis. This is a medical emergency and can be fatal.
It happens when your blood sugar level is very high and you don't have enough insulin in your body.
What causes chronic (long term) vomiting?
Vomiting can be a symptom of a chronic (ongoing) health problem. If vomiting continues for longer than a few days, see your doctor.
Medicines
Nausea or vomiting can be a side effect of many medicines. Examples of medicines that can cause vomiting are:
- non-steroidal anti-inflammatory medicines (NSAIDs)
- nicotine patches
- anti-arrhythmic (medicines that suppress abnormal heart rhythms)
- metformin (a diabetes medicine)
- some antibiotics
- anticonvulsants
To find out about your medicine, you can talk to your pharmacist or read the consumer medicine information. Sometimes it is included in the pack, or you can search for it..
If you suspect that a medicine is causing vomiting, speak to your doctor or pharmacist. They can advise you and may be able to substitute it with another medicine.
Substance abuse can also cause vomiting.
Chemotherapy medicines
Nausea and vomiting can be a side effect of chemotherapy. These symptoms usually start a few hours after treatment.
Tell your nurse or doctor if you feel sick. They may be able to give you medicine to stop the vomiting (antiemetic medicines).
Radiation treatments
Nausea or vomiting can be a side effect of radiotherapy. If you suffer from nausea or vomiting after treatments, tell the radiation oncologist or nurse.
They may be able to give you antiemetic medicines to stop your symptoms.
Vitamins
High doses of some vitamins can cause vomiting. Remember to tell your doctor or pharmacist about everything you are taking, including herbs, vitamins and other complementary medicines.
Pregnancy
Morning sickness is common during early pregnancy. It involves nausea and vomiting at any time of the day, but often in the morning.
Usually, your symptoms will improve after the first 3 months of pregnancy. Hyperemesis gravidarum (Opens in new tab) is a more serious level of vomiting during pregnancy.
Migraine
Nausea and vomiting are common symptoms of a migraine. You might vomit in the headache phase, after the aura — if you have one.
Food allergies
Food allergies can cause ongoing digestive symptoms including:
- vomiting
- diarrhoea
- constipation
- flatulence (wind)
- bloating
If you have symptoms shortly after eating see your doctor or a dietitian for advice.
Upper digestive tract disorders
If you often vomit after meals, this could be caused by gastro-oesophageal reflux disease GORD.
Gastroparesis
Gastroparesis is a delayed emptying of the stomach due to nerve damage. It can lead to nausea and vomiting after meals.
Kidney stones
Nausea and vomiting are symptoms of kidney stones, along with gripping pain in your back.
Functional nausea and vomiting
Functional nausea and vomiting is the name given to chronic nausea and vomiting when there is no clear medical cause.
Cyclic vomiting syndrome is a rare syndrome that is a type of functional nausea and vomiting.
Resources and support
To learn more about long term causes of digestive problems, try this resource The Gut Foundation (Opens in new tab).
If you need to speak to someone about vomiting, call healthdirect on 1800 022 222 to speak with a registered nurse, 24 hours, 7 days a week.
Find out how we develop and review our content.
Last reviewed: February 2024
Need more information?
These trusted information partners have more on this topic.
Top results
Vomiting in children and teenagers | Raising Children Network
Vomiting in children is common. The biggest risk is dehydration, so make sure your child gets enough fluids. Take your child to the GP if you’re worried.
Diarrhoea and vomiting
There are many causes of diarrhoea and vomiting, the most common being viral. Other symptoms such as headache, fever, generalised aches and pains and tiredness may also be present.
Nausea and vomiting - Liver Foundation
Tummy problems are common in people who have liver disease. If you lost your appetite in the early stages, as your disease gets worse you may start to feel sick or keep vomiting. Call an ambulance or go straight to the Emergency Department if you have liver disease and you…
Nausea and vomiting | Cancer Australia
Anti-nausea medication, bland foods, small meals, rest, avoidance of triggers, and acupuncture may help alleviate nausea symptoms.
Gastroenteritis factsheet
Gastroenteritis, or gastro, is common in babies and children. It causes cramps, vomiting, and diarrhoea.
Food poisoning in children and teenagers | Raising Children Network
Food poisoning is a type of gastroenteritis, usually caused by germs in contaminated food. Symptoms include nausea, vomiting, stomach pain and diarrhoea.
Serious childhood illnesses: 0-3 years | Raising Children Network
Seek immediate medical help for symptoms of serious childhood illness, like severe drowsiness, breathing difficulty, blue skin, seizures, fever and vomiting.
Morning sickness
Morning sickness is the nausea and vomiting experienced by many women during pregnancy. It affects between 70 to 85 per cent of pregnant women.
Dehydration & fluid loss: children & teens | Raising Children Network
Dehydration can happen if children have diarrhoea, vomiting or not enough fluid, or they exercise or sweat a lot. Treat dehydration by giving extra fluids.
Related pages
Search our site for
Symptom Checker
Worried about your health?
Select a symptom, answer some questions, get advice