Gallstones | Kōwhatu kouawai

Key points about gallstones

  • Gallstones (kōwhatu kouawai) are hard clumps that look like pebbles or stones, which form in the gallbladder from a fluid called bile. If the bile contains too much cholesterol or waste products, it can harden into gallstones.
  • Gallstones are common, particularly in women. It is estimated that, from the age of 40, more than 20 out of 100 women, and 10 out of 100 men, have gallstones.
  • Most people do not even notice that they have gallstones: about 80 out of 100 people with gallstones have no symptoms over a period of 15 years.
  • Gallstones can range in size from a grain of sand to a golf ball and can cause sudden abdominal (tummy) pain. This pain, called a gallbladder attack, occurs when these gallstones block or irritate the gallbladder.
  • Gallstones are usually only treated if they cause pain.
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The gallbladder is part of your digestive system. It is a small, pear-shaped sac that sits underneath your liver. It stores and concentrates bile, a greenish-yellow fluid made in your liver. Bile helps to digest fats in the food you eat.

Image credit: Canva

Gallstones can range in size from small crystals to the size of a golf ball. They develop when bile becomes too concentrated in the gallbladder. Substances in bile clump together to form 'stones'. 

When gallstones stay in the gallbladder, the condition is called cholelithiasis. When they enter the main outlet (bile duct), the condition is called choledocholithiasis. If they are blocking a duct you will probably need treatment.

Types of gallstones

Cholesterol stones are the most common type, making up at least three-quarters of all gallstones. They can occur if your liver produces too much cholesterol which causes too much cholesterol in your bile.

Pigment stones are less common. They are small and dark brown or black in colour and tend to occur in people with other types of stomach or blood disorders.

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About 1 in 10 New Zealanders have gallstones, although most will not get any symptoms. 

People at risk of gallstones
  • women: are twice as likely as men to have gallstones between the ages of 20 and 60 years
  • pregnant women
  • women using the contraceptive pill or hormone replacement therapy
  • increasing age: about 15 out of every 100 elderly people have gallstones
  • overweight or obese people, due to their increased cholesterol levels
  • people who lose weight rapidly because burning fat stores causes your liver to secrete extra cholesterol into your bile
  • people with a family history of gallstones
  • people with diabetes
  • some people who take cholesterol-lowering medicines

A gallstone attack can happen at any time but it is more likely to occur after eating a fatty meal. Gallstone attacks can range from pain that happens now-and-again, causing a ‘grumbling’ discomfort to unbearably painful attacks that can last for hours. The most common symptom is an attack of pain in the upper right part of your belly, or your back, known as biliary colic.

Symptoms of gallstones can include the following:

  • Pain: constant, severe pain in the upper right section of your stomach that may be felt through to your back between the shoulder blades. It can also occur centrally in your upper abdomen or behind your breastbone, copying a heart attack. The pain increases quickly and may last from 15 minutes to several hours before easing.
  • Nausea (feeling sick) and vomiting (being sick).
  • Indigestion, flatulence (wind) or general discomfort in the tummy.
  • Not being able to eat fatty foods.

Gallstones sometimes require immediate attention

Serious symptoms of gallstones that require immediate attention include:

  • fever, sweating and chills
  • jaundice – a yellowing of your skin or whites of your eyes.

Fever may be an indication of infection or inflammation of your gallbladder or your pancreas. The pancreas is a nearby digestive gland that produces insulin and digestive enzymes. Jaundice occurs when the main bile duct becomes blocked, leading to the build-up of a substance called bilirubin in the bloodstream.

Several other conditions can cause symptoms similar to gallstones, so it is important that you seek advice from your doctor to rule out other causes such as cardiac disease, indigestion, hepatitis, irritable bowel syndrome or gastric ulcers.

Silent gallstones

In most cases, gallstones don’t cause any problems, and 7 out of 10 people have no symptoms. These gallstones are often only discovered by chance during investigations of other problems. For this reason, they are sometimes called ‘silent’ gallstones.

  • If you are found to have silent gallstones you should avoid fatty meals.
  • It is not likely you will require surgery unless you develop symptoms or pain.
  • It is important to weigh up the risk, expense and discomfort of having your gallbladder removed (called a cholecystectomy) against the fact that the stones may never cause you any discomfort or illness.

The type of tests used to diagnose gallstones depends on the situation. 

Blood tests may be used to check for infection, jaundice or blockage in the bile ducts.

Ultrasound is the most common test used to check for gallstones. It is quick and painless and uses high-frequency sound waves to create pictures of the gallbladder, bile duct, and their contents. Read more about ultrasound.

Endoscopic retrograde cholangiopancreatography (ERCP) is an investigation your doctor may request if it is suspected that a gallstone may be lodged in the main bile duct and cannot be detected using ultrasound. This procedure involves looking at the bile duct through a flexible tube called an endoscope, which is inserted into your mouth and directed carefully through your oesophagus and stomach. It is then passed into your duodenum, where the opening of the bile duct can be seen. A dye is injected through the tube into the bile duct to check if there are any blockages.

Sometimes, a sphincterotomy is carried out during the ERCP. This involves passing an instrument through the endoscope and making a small cut in the lower part of the bile duct, which you should not feel. This should allow the surgeon to remove any stones, catching them in a tiny basket.

Magnetic resonance cholangiopancreatography (MRCP) is an MRI scan to form a picture of the bile ducts and pancreatic ducts to look for narrowings. This is done to clarify the diagnosis prior to consideration of an ERCP if there is any doubt or if an ERCP is considered high risk.

In most cases, gallstones are treated only if you have symptoms. Your doctor will give you medicine for pain, nausea, and vomiting. You may be told to drink only clear liquids for a few days to give your gallbladder a rest. You should also avoid fatty or greasy foods. If you're in a lot of pain, you may be admitted to the hospital so you can get intravenous fluids (through your veins), pain medicine and antibiotics.

Wait-and-see approach

About 3 in 10 people who get biliary colic will not get another attack. In these cases, the stone dissolves or becomes dislodged on its own. Because of this, your doctor may advise a wait-and-see approach. If you are using the wait-and-see approach, there are a number of things you can do to reduce the chance of having more gallstone attacks, such as:

  • eat a healthy balanced diet with plenty of fruit and vegetables
  • start a slow weight loss until you reach a healthy weight (avoid crash diets)
  • drink plenty of fluids to keep hydrated
  • limit the amount of caffeine and alcohol you consume
  • keep a diary of food and symptoms to help you identify “trigger foods”
  • avoid fatty foods and excess oils when cooking as these make the gallbladder squeeze and can bring on a painful attack.


An operation to remove the gallbladder is called cholecystecomy and is the most common way of treating gallstones. You can live a healthy life without your gallbladder. Read about gallbladder removal surgery.


Some people find eating a low-fat diet controls their symptoms of gallstones. However, if you have a fever, constant nausea or vomiting, or if you have jaundice (yellow eyes or skin), seek medical attention.

Home remedies

Remedies are advertised on the internet as being able to ‘cure’ or ‘pass’ gallstones. These usually involve drinking large amounts of oil and lemon juice. They do not work. Any apparent ‘success’ is because the symptoms from gallstones can be very rare, leading to the belief that a ‘cure’ has been achieved – until the next attack of pain.

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Credits: Healthify editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Dr Derek JY Luo 羅佳昀醫生 MBChB (Otago) FRACP Consultant Gastroenterologist, Auckland

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