Gallstones

What are gallstones?

Gallstones, also known as cholelithiasis, are small, pebble-like substances that form within the gallbladder, an organ located just below the liver. The gallbladder plays a vital role in digestion, storing, and concentrating bile—a fluid the liver produces to help digest fats. Gallstones can vary widely in size and composition, with some being as tiny as a grain of salt, while others can grow to the size of a golf ball. 

There are two main types of gallstones; these are:

• Cholesterol gallstones: cholesterol gallstones are the most common type of gallstone. They are yellow and are made of undissolved cholesterol and other elements such as bilirubin and calcium salts.
• Pigment gallstones: pigment gallstones are black or brown and composed of bilirubin. They typically occur due to excess bilirubin in bile.

The formation of gallstones can interrupt the normal flow of bile from the gallbladder to the small intestine, leading to digestive problems and discomfort. 

What causes gallstones?

Gallstones result from imbalances in substances that make up bile. Excess cholesterol in the bile can lead to cholesterol stones, while too much bilirubin can cause pigment stones. Several factors contribute to these imbalances, including:

• Bile contains too much bilirubin: bilirubin is a waste product produced by the breakdown of red blood cells. Pigment gallstones may form when the liver produces too much bilirubin due to conditions such as liver cirrhosis, blood disorders, and biliary tract infections.
• Bile contains too much cholesterol: bile produced by the gallbladder helps dissolve cholesterol made by the liver. However, if more cholesterol is produced than the bile can dissolve, the excess undissolved cholesterol will crystallise and form cholesterol gallstones.
• Inefficient emptying of the gallbladder: if the gallbladder does not empty sufficiently or frequently enough, bile will build up and become concentrated, leading to gallstones formation.

What are the symptoms of gallstones?

While many people with gallstones do not experience any symptoms (asymptomatic gallstones), those who do may face what's known as a gallbladder attack. These attacks are characterised by:

• Mild symptoms include bloating and feeling of indigestion
• More severe symptoms include:

• Intense pain in the upper right abdomen or middle of the breastbone
• Pain in the back between the shoulder blades or under the right shoulder blade
• Nausea or vomiting accompanying the pain

These symptoms typically occur because a gallstone is blocking the outflow of the gallbladder, causing increased pressure and irritation. Gallbladder attacks often follow fatty meals and might happen during the night.

Who is at risk of gallstones in Singapore?

Risk factors for developing gallstones include:

• Gender: females are two to three times more likely to develop gallstones than males.
• Pregnancy: hormone levels are elevated during pregnancy, leading to higher cholesterol levels and reduced gallbladder emptying. These factors contribute to the development of gallstones.
• Obesity: studies have shown that obese individuals are more likely to develop gallstones than those with a healthy body mass index.
• Rapid weight loss: individuals who have undergone rapid weight loss are at an increased risk of developing gallstones.
• Lipid levels: individuals with high cholesterol or low high-density lipoprotein (HDL) are more prone to gallstones.
• Medical conditions: certain medical conditions such as diabetes, liver cirrhosis, Crohn’s disease, anaemia, and bile duct infection are linked to a higher risk of developing gallstones.
• Age: the risk of developing gallstones increases with age.
• Genetic predisposition: some individuals are genetically inclined to develop gallstones. 
• Lifestyle factors: a high-fat, low-fibre diet and a sedentary lifestyle contribute to the risk of developing gallstones.

How are gallstones diagnosed?

Diagnosing gallstones in Singapore involves a combination of symptom evaluation, physical examinations, and imaging tests.

• Ultrasound: ultrasounds are the primary diagnostic tool to visualise and effectively diagnose stones within the gallbladder.
• Computed tomography (CT) scans: CT scans provide detailed images and can help detect calcified gallstones or associated complications such as gallbladder infection.
• Magnetic resonance cholangiopancreatography (MRCP): MRCP is a special type of magnetic resonance imaging (MRI) that focuses on the bile ducts, pancreas, and gallbladder. It is highly accurate in detecting bile abnormalities. 
• Endoscopic ultrasound (EUS): an EUS involves inserting a thin, flexible tube through the mouth to the stomach and small intestine to capture close images of the gallbladder, bile duct and pancreas.
• Blood test: blood tests can also help check for signs of infection, inflammation, or blocked bile ducts.

What are the treatment options for gallstones in Singapore?

Treatment for gallstones in Singapore is tailored to the individual's symptoms and the presence of complications. A watchful waiting approach is recommended for asymptomatic gallstones, with advice on lifestyle adjustments to prevent symptoms from developing. 

However, more definitive treatments are necessary once gallstones become symptomatic or complications arise.

• Cholecystectomy: the standard treatment for symptomatic gallstones is a cholecystectomy, the surgical removal of the gallbladder. This procedure is most commonly performed laparoscopically (keyhole), known as laparoscopic cholecystectomy. It involves making small incisions through which surgical tools and a camera are inserted, allowing the surgeon to remove the gallbladder with minimal invasiveness. This method offers the benefits of reduced pain, shorter hospital stays, and quicker recovery compared to traditional open surgery.
• Medication: medications such as oral bile acid pills may be prescribed. These pills can dissolve cholesterol gallstones over time. However, this method is less commonly used due to its slow action, side effects, poor efficacy and the potential for stones to recur.
• Endoscopic retrograde cholangiopancreatography (ERCP): if gallstones have migrated into the bile duct, an ERCP may be performed. This procedure combines endoscopy and X-ray imaging to locate and remove stones from the bile duct, often in conjunction with surgery to remove the gallbladder, as most stones originate from the gallbladder.

Frequently asked questions

Are gallstones painful?

Yes, gallstones can be quite painful, particularly during a gallbladder attack. The pain is often severe and may require emergency medical attention. However, not everyone with gallstones will experience pain; some people may remain symptom-free for years.

Can gallstones go away on their own?

Gallstones do not go away without treatment. The most effective treatment for gallstones is gallbladder removal or cholecystectomy. Even if gallstones are dissolved through medication or removed through ERCP, if it has dropped into the bile duct, they will recur. 

What is the most common treatment for gallstones?

A cholecystectomy, or gallbladder removal, is the most common and most effective treatment for gallstones.