Gallstones are stone-like deposits that form in the gallbladder from a thickened digestive fluid called bile.

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.

Key points

  1. Gallstones are caused when bile becomes too concentrated and forms clumps (stones).
  2. 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.
  3. 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.
  4. Gallstones are usually only treated if they cause pain.

What is the gallbladder and what does it do?

The gallbladder is sometimes easily forgotten, overshadowed (literally) by the liver and other parts of the digestive system. The gallbladder is a small, pear-shaped sac-like organ 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.

Many people don't know where the gall bladder is or what it does. But it's worth paying attention to this critical part of your body – particularly if you are a woman or a woman during pregnancy. If things go wrong with your gallbladder, it can sometimes be very painful.

What are gallstones?

Gallstones – which can range in size from minute crystals to the size of a golf ball – develop when bile becomes too concentrated in the gallbladder. Substances in bile clump together to form 'stones'. They can be as small as a grain of sand or as large as a golf ball. 

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,ie, there is 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 gastrointestinal or blood disorders.

Who is at risk of gallstones?

About one in 10 New Zealanders have gallstones, although most will not get any symptoms. People at risk of gallstones are:

  • women – twice as likely as men to have gallstones between the ages of 20 and 60 years
  • pregnant women
  • elderly people - about 15% of elderly people have gallstones
  • overweight or obese people – due to their increased cholesterol levels
  • people who lose weight rapidly – burning fat stores causes your liver to secrete extra cholesterol into your bile
  • women using the contraceptive pill or hormone replacement therapy
  • people with a family history of gallstones
  • people with diabetes
  • some people who take cholesterol-lowering drugs.

"Female, fair, fat and forty" - this is a common phrase for increased risk of gallstone problems.


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 occasional, unpredictable ‘grumbling’ to excruciatingly 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 the back, known as biliary colic.

Symptoms of gallstones can include:

  • Constant, severe pain in the upper right section of the stomach that may be felt through to the back between the shoulder blades. It can also occur centrally in the upper abdomen or behind the breast bone, mimicking a heart attack. The pain increases quickly and may last from 15 minutes to several hours before easing.
  • Nausea and vomiting.
  • Indigestion, flatulence (wind) or general discomfort in the abdomen.
  • Intolerance to fatty foods.

Gallstones sometimes require immediate attention

Serious symptoms of gallstones that require immediate attention include:

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

Fever may be an indication of infection or inflammation of the gallbladder, or of the pancreas. The pancreas is a nearby digestive gland that produces insulin and digestive enzymes. Jaundice, on the other hand, 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.

Non-symptomatic (silent) gallstones

About 70% of people who have gallstones have no noticeable symptoms and are often unaware of their presence. These gallstones are often only discovered during evaluation 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 technique used to diagnose gallstones depends on the situation. Diagnosis is usually 98% reliable, but false-positive results - where there are in fact no gallstones present - can occur in a few cases.

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

Ultrasound is the most common technique used to confirm gallstones. It is quick and painless and uses high-frequency sound waves, sent through a hand-held device that is moved across your abdomen. The echoes from sound waves bouncing off the gallbladder and other organs are converted to electrical impulses that create a picture on a video monitor.

Cholangiography is a procedure where dye is injected directly into the main bile ducts and a series of x-rays are taken to reveal any obstructions or lesions in the ducts.

Cholecystography is a procedure where dye is injected into your body and a series of x-rays taken to reveal the structure of your gallbladder and its movement. Any obstruction of another duct, the cystic duct, will also show up.

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 maneouvered 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 any blockages are present.

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.



Surgical removal of the gallbladder (cholecystecomy) is the most common way of treating gallstones – you can live without your gallbladder. 

  • The procedure to remove the gallbladder is called a cholecystectomy and is mostly performed laparoscopically.
  • This type of ‘keyhole surgery’ usually involves four small incisions for the narrow camera and instruments to enter the abdomen.
  • Laparoscopic surgery generally means a quick recovery and minimal pain and scarring.
  • You can usually go home on the day of the operation or the morning after and any pain can be treated with paracetamol or anti-inflammatory medications.

Once the gallbladder has been removed, most people make a full recovery and function normally. However, about 4% of people become intolerant to fatty foods and may have to eliminate them from their diet. 


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.

A word about internet remedies

Remedies are touted 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 ‘success’ is because the symptoms from gallstones can be very infrequent, leading to the belief that a ‘cure’ has been achieved – until the next attack of pain.

Credits: Health Navigator, reviewed by Dr Andrew Bowker, Laparoscopy Auckland 2008. Image credits: Reviewed By: Health Navigator Last reviewed: 01 Jan 2015