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What are gallstones?
Gallstones are small, hardened deposits that form inside the gallbladder, a small organ located beneath the liver in the upper right quadrant of the abdomen. The medical term for this condition is cholelithiasis.
Bile is a digestive fluid produced by the liver and stored in the gallbladder until the body needs it to help digest fats. When fat-containing food enters the small intestine, the gallbladder contracts and pushes bile into the bile duct, a small tube that connects the gallbladder to the intestine, where it helps break down dietary fat.
If bile does not flow smoothly through this system, it can solidify into stones, potentially leading to inflammation of the gallbladder, the bile ducts themselves, or, in rare cases, the liver.
The common hepatic duct also connects with other ducts, including the pancreatic duct, through which digestive enzymes produced by the pancreas pass into the intestine. In some cases, a gallstone that migrates into the common bile duct can trigger inflammation of the pancreas, a condition known as acute pancreatitis, which is extremely painful and can potentially become life-threatening.
The mere presence of gallstones does not necessarily cause symptoms. Symptoms typically appear only when a stone prevents the gallbladder from emptying normally. When this happens, a patient may experience:
- nausea and vomiting,
- abdominal pain, pain in the back, or pain in the right arm.
These symptoms typically appear shortly after eating and are collectively referred to as biliary colic.
If one of the bile ducts remains blocked for a long enough period, the gallbladder, liver, or pancreas can sustain serious damage or develop a severe infection which, if left untreated, can even become fatal. Symptoms suggestive of a higher risk of complications include:
- fever,
- jaundice (yellowing of the skin and eyes),
- continuous pain that is not limited to episodes after eating.
Silent gallstones that cause no symptoms generally require no treatment, while gallstones causing recurrent colic are typically managed with surgical removal of the gallbladder.
Where is the gallbladder located?
The gallbladder is a small, pouch-like organ located on the right side of the body, tucked just beneath the liver.
Causes
A quick review of anatomy and physiology
Bile is composed of:
- water,
- cholesterol,
- fats,
- bile salts,
- proteins,
- and bilirubin, a waste product that is eliminated in the stool.
Bile salts break down dietary fats, while bilirubin gives bile and stool their characteristic yellowish-brown color. If bile contains too much cholesterol, too many bile salts, or too much bilirubin, it can begin to crystallize, forming gallstones.
The biliary system consists of the gallbladder and a network of ducts that allow bile and other digestive enzymes to travel from the liver, gallbladder, and pancreas into the small intestine.
Gallstones can obstruct the flow of bile if they move out of the gallbladder and become lodged in one of the small tubes that allow bile to pass from the liver to the small intestine. The main ducts involved include:
- the hepatic ducts, through which bile exits the liver,
- the cystic duct, which allows bile to move to and from the gallbladder,
- the common bile duct, through which bile from the cystic and hepatic ducts flows toward the small intestine.
When and why do gallstones form?
There are two main types of gallstones:
- cholesterol stones,
- pigment stones.
Cholesterol stones are usually yellowish or greenish in color and are made primarily of solidified cholesterol. They account for roughly 80 percent of all gallstones. It is believed that they form when bile contains too much cholesterol, too much bilirubin, or too few bile salts, or when the gallbladder fails to empty completely or frequently enough. The exact causes of these imbalances are not fully understood.
Pigment stones, on the other hand, are smaller, darker, and made mostly of bilirubin. They can range in size from a grain of sand to as large as a golf ball. A person may develop a single stone, hundreds of tiny stones, or a combination of both sizes within the gallbladder. The exact cause remains unclear, but people with liver cirrhosis, biliary tract infections, or inherited blood disorders (such as sickle cell anemia), in which the liver produces excess bilirubin, appear to be at higher risk.
In most cases, patients do not develop a single stone but rather multiple crystallized stones over time.
Risk factors
Other factors that contribute to gallstone formation, particularly cholesterol stones, include:
Non-modifiable factors:
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Age. People over the age of 60 are at greater risk than younger individuals. As the body ages, it tends to secrete more cholesterol into bile.
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Sex. Women are roughly twice as likely as men to develop gallstones. Excess estrogen, whether related to pregnancy, hormone replacement therapy, or hormonal contraceptive methods, increases cholesterol levels in bile and reduces gallbladder motility, both of which can promote gallstone formation.
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Family history. Gallstones often run in families and may have a genetic component.
Modifiable factors:
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Body weight. Large-scale research has suggested that being overweight, even moderately, increases the risk of developing gallstones. The most likely explanation is that the proportion of bile salts in bile is reduced relative to cholesterol. This increase in cholesterol reduces how often the gallbladder empties. Obesity is one of the leading risk factors for gallstones, particularly in women.
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Diet. A diet excessively high in fat and cholesterol and low in fiber increases the risk of gallstones, because the resulting rise in bile cholesterol reduces how frequently the gallbladder empties.
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Rapid weight loss. During periods of fasting or rapid weight loss, the liver secretes more cholesterol into bile, which can promote stone formation. In these situations, the gallbladder also tends to empty less regularly.
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Cholesterol-lowering medications. Medications that lower blood cholesterol levels can increase the amount of cholesterol secreted into bile, thereby predisposing to gallstones. However, research has shown that long-term use of statins is actually associated with a protective effect against gallstones.
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Diabetes. People with diabetes commonly have elevated triglycerides, a type of fatty acid that can increase the risk of developing gallstones.
Animal research has helped identify several genes that may be present in patients who are more prone to gallstones. Although the known risk factors are numerous and well documented, researchers continue to search for the specific genetic variants that increase susceptibility, and many believe the ongoing global rise in obesity rates may be driving an increase in gallstone incidence worldwide.
Symptoms
Many patients with gallstones experience no symptoms at all, a situation referred to as “silent gallstones”, meaning stones that do not interfere with the function of the gallbladder, liver, or pancreas.
It is estimated that up to 25 percent of the population develops gallstones over their lifetime, but only 20 to 50 percent of these individuals ever develop symptoms, which are sometimes discovered incidentally during imaging performed for unrelated reasons.
When gallstones move into the bile ducts and cause an obstruction, pressure builds up inside the gallbladder, triggering the onset of symptoms. The discomfort resulting from bile duct obstruction is generally referred to as “biliary colic” and tends to occur suddenly. Attacks usually follow a particularly heavy or fatty meal and can also occur at night.
Typical symptoms of biliary colic caused by gallstones include:
- constant pain in the upper right quadrant of the abdomen, which increases rapidly in intensity and can last from thirty minutes to several hours,
- back pain felt between the shoulder blades,
- pain beneath the right shoulder.
In more severe cases, the following may also appear:
- nausea and vomiting,
- fever and/or chills,
- diarrhea (with pale, soft stools),
- jaundice or mild jaundice (yellowish discoloration of the eyes and skin).
When to call a doctor
Because the symptoms of gallstones can closely resemble those of other abdominal conditions, such as heart attack, appendicitis, peptic ulcer, irritable bowel syndrome, hiatal hernia, pancreatitis, or hepatitis, it is essential to reach an accurate and timely diagnosis.
If you believe you may be experiencing a gallstone attack, contact your doctor promptly. Attacks often resolve on their own once a stone shifts position, but the gallbladder can become infected or damaged if the obstruction persists.
It is advisable to seek emergency medical care if you experience:
- pain lasting more than five hours,
- nausea and vomiting,
- fever, even mild, or chills,
- yellowish discoloration of the skin or eyes,
- unusually pale or light-colored stools.
Dangers and complications
Gallstones cause pain because they obstruct the cystic duct. If this obstruction continues for more than a few hours, the gallbladder can become inflamed.
This condition, known as acute cholecystitis, can cause fever, intense and continuous pain, and can progress to a gallbladder infection. Hospitalization is usually required for observation, antibiotic and pain-relief therapy, and, in many cases, surgery.
If a stone moves from the cystic duct into the common bile duct, more serious complications can develop:
- if the stone becomes lodged in the common bile duct, it can lead to a serious infection of the duct itself,
- if it becomes lodged near the point where the bile duct and pancreatic duct meet, it can trigger inflammation of the pancreas (pancreatitis), since the pancreas and liver share a common excretory duct.
Both of these situations can be dangerous. Bile duct stones typically cause fever, pain, and jaundice (yellowish discoloration of the eyes and skin), sometimes accompanied by itching.
In patients with asymptomatic gallstones discovered incidentally, the likelihood of developing symptoms or complications is estimated at between 1 and 2 percent per year.
Diagnosis
The modern diagnostic approach to gallstones aims not only to confirm the presence of stones, but above all to rule out complications such as infection or duct obstruction. The process begins with a careful clinical evaluation, during which the doctor assesses the location of the pain and checks for signs such as jaundice.
First and second-level imaging
Abdominal ultrasound remains the gold standard and the first-choice test: it is quick, non-invasive, and highly sensitive for detecting gallstones, even small ones, within the gallbladder. However, in more complex clinical situations, additional testing may be required:
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Magnetic Resonance Cholangiopancreatography (MRCP): This is currently the preferred test for examining the bile ducts without exposure to radiation or the need for invasive procedures. It allows for extremely precise identification of stones that have migrated from the gallbladder into the common ducts.
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Abdominal CT scan: Although less sensitive than ultrasound for detecting small cholesterol stones, CT is essential for evaluating complications such as pancreatitis or perforation, and for ruling out other causes of acute abdominal pain.
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Endoscopic ultrasound (EUS): An advanced technique that combines endoscopy with ultrasound imaging. It is useful in uncertain cases, when stones are very small (microlithiasis) or difficult to visualize using conventional methods.
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Endoscopic Retrograde Cholangiopancreatography (ERCP): Rarely used today for purely diagnostic purposes, ERCP is now used mainly for therapeutic intervention, allowing doctors to remove a stone obstructing the bile duct during the same procedure.
Laboratory tests
Blood tests provide crucial information about the condition of the organs involved. Key parameters monitored include:
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Liver function tests: Elevated levels of bilirubin, transaminases, and alkaline phosphatase suggest bile duct obstruction or liver inflammation.
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Inflammatory markers: A complete blood count (to check white blood cell levels) and C-reactive protein (CRP) help identify an ongoing infection, such as cholecystitis.
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Pancreatic enzymes: Measuring amylase and lipase is essential to rule out pancreatic involvement.
Treatment
The modern therapeutic approach to gallstones is highly individualized and depends on the presence of symptoms, the frequency of colic episodes, and the risk of complications. The primary goal is to relieve pain and prevent permanent damage to the liver and pancreas.
Managing asymptomatic gallstones
For patients whose gallstones are discovered incidentally and who have never experienced symptoms, current scientific consensus recommends what is known as “watchful waiting”. Preventive surgery is not generally recommended unless specific risk factors are present, such as anatomical abnormalities or certain blood disorders. Patients are typically advised to undergo periodic monitoring and to adopt a healthy lifestyle.
Treating an acute attack
When a patient experiences an episode of biliary colic, the priority is pain control. Nonsteroidal anti-inflammatory drugs (NSAIDs) or antispasmodic medications are generally used. If pain persists or is accompanied by fever, hospitalization is necessary to administer intravenous fluids and antibiotics, stabilizing the patient in preparation for possible surgery.
Surgical options
Cholecystectomy (surgical removal of the gallbladder) is the definitive treatment for symptomatic gallstone disease.
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Laparoscopic cholecystectomy: This is the current standard of care. Through three or four small incisions, the surgeon removes the gallbladder with the aid of a camera. Thanks to modern Enhanced Recovery After Surgery (ERAS) protocols, recovery is remarkably fast: most patients return home within 24 to 48 hours and resume normal activities within about a week.
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Open cholecystectomy: Reserved for exceptional cases, such as extremely severe inflammation, adhesions from previous surgeries, or complex anatomical abnormalities that would make the laparoscopic approach unsafe.
Medical and alternative therapies
For patients who cannot or prefer not to undergo surgery, less invasive options exist, though they carry a relatively high rate of recurrence, meaning stones tend to reform over time:
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Medication. Ursodeoxycholic acid can dissolve small, pure cholesterol stones. However, this treatment requires a long course, typically from 6 to 24 months, and is only successful in a limited subset of patients.
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Extracorporeal shock wave lithotripsy. The use of shock waves to break up gallstones is far less common today than in the past and is now limited to very specific cases in which surgery is contraindicated.
The importance of lifestyle
Changing dietary habits is an integral part of managing gallstone disease. A balanced diet helps prevent the formation of new stones in patients who have not had surgery, and helps manage the occasional digestive symptoms that can occur after surgery.
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Weight management. Being overweight is a key risk factor, but it is important to avoid crash diets or prolonged fasting, which can paradoxically accelerate gallstone formation. Weight loss should be gradual, ideally around 0.5 to 1 kilogram (roughly 1 to 2 pounds) per week.
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Food choices. It is helpful to increase fiber intake (fruit, vegetables, whole grains) and to favor unsaturated fats (olive oil, nuts) over saturated fats. Staying consistently well hydrated is equally important for keeping bile fluid and flowing properly.
Diet: what to eat
Susceptibility to gallstones is also influenced by diet.
Some patients may feel better on a low-fat diet, but this is not necessarily the best choice for everyone. It is generally recommended to include a moderate amount of dietary fat, as consuming fat stimulates the gallbladder to contract and release bile. Dietary recommendations should be individualized based on symptoms, overall health, and guidance from a healthcare professional. General nutrition guidelines typically emphasize a balanced diet with an appropriate intake of healthy fats rather than complete fat restriction.
Although a fat intake between 20 and 35 percent of total daily energy can be considered appropriate for a balanced diet, it is advisable not to exceed 30 percent of daily energy intake, in order to avoid compromising adequate intake of other macronutrients, such as carbohydrates and protein.
It is recommended to prioritize healthy fats, typically derived from plant-based foods.
A low-fat diet can be helpful in cases of steatorrhea (pale, yellow, orange, or oily stools that may float or have an unusually strong odor). It is worth remembering, however, that the body still requires a small amount of dietary fat, specifically the so-called “essential fats”, linoleic acid and alpha-linolenic acid, which must be regularly obtained through diet since the body cannot produce them on its own.
Fruits and vegetables, likely thanks in part to their fiber content, have been shown to reduce the risk of gallstone formation.
To reduce the risk of gallstones associated with weight loss, it can help to follow a few practical strategies, such as aiming for gradual rather than rapid weight loss. Depending on your starting weight, it is generally recommended to aim for a loss of between roughly 250 grams and one kilogram (about half a pound to two pounds) per week. This rate of weight loss can typically be sustained for up to six months, after which weight loss tends to slow and stabilize as the body adapts by burning fewer calories overall.
It is also possible to reduce the gallstone risk associated with weight fluctuations by aiming for a somewhat more modest weight loss goal than originally planned. Even a 5 to 10 percent reduction in body weight over six months or more can meaningfully improve the health of an overweight or obese adult.
Finally, regular physical activity is associated with a lower risk of gallstones. Aim for roughly one hour of activity, even at a moderate intensity, on most days of the week to help control body weight and prevent weight gain. To maintain the benefits of dietary changes over time, try to engage in at least one hour to ninety minutes of moderate physical activity daily.
What NOT to eat
Because cholesterol appears to play a significant role in gallstone formation, it is advisable to reduce consumption of foods high in saturated fat, including:
- sausages and fatty cuts of meat in general,
- butter and other animal fats such as lard,
- cheese,
- cakes and cookies,
- foods containing coconut oil or palm oil.
More broadly, current guidelines recommend adopting a genuinely healthy diet in the fullest sense of the term, one that can also support gradual, sustainable weight loss when needed.
Frequently asked questions
What is the gallbladder?
The gallbladder is a small organ whose function is to store bile, a digestive fluid produced by the liver that helps the body absorb dietary fats. It is a useful organ, but not essential to life. Its surgical removal generally does not cause long-term complications or significant digestive difficulties.
Where is the gallbladder located? On the right or left side?
The gallbladder is a small, pouch-shaped organ located on the right side of the body, just beneath the liver.
What should I eat if I have gallstones?
If you are trying to lose weight, it is especially important that weight loss be gradual, since overly aggressive weight-loss regimens are associated with an increased risk of developing gallstones. It is also important to eat regularly throughout the day, favoring small, frequent meals, since this helps promote periodic emptying of the gallbladder. In terms of food choices, the general advice can be summarized as follows: reduce animal-derived foods and increase the consumption of plant-based foods. Saturated fats are associated with gallstone development, unlike monounsaturated and polyunsaturated fats. It is also advisable to increase fiber intake (whole grains, legumes, fruit, and vegetables) and reduce foods high in refined sugars.
What should I NOT eat if I have gallstones?
It is recommended to reduce or eliminate animal-derived foods from the diet, particularly the fattier varieties, as well as refined sugars, always favoring whole-grain alternatives when possible. Caution is also advised with heavily processed, industrially produced foods, which are often high in saturated fatty acids similar to those found in animal products. Avoid fried foods and use extra virgin olive oil as your primary source of added fat.
Where does gallbladder pain occur?
The characteristic symptoms of gallstones include nausea, vomiting, and abdominal pain, which can also radiate to the back and/or the right arm.
What should I do about the pain?
If you experience pain consistent with gallstones, it is recommended that you contact your doctor to determine together whether anti-inflammatory medication alone is sufficient or whether surgery may be necessary.
Can gallstones reform after gallbladder removal (cholecystectomy)?
Yes, it is possible for stones to form in the bile duct even after the gallbladder has been removed, even though the gallbladder itself is no longer present.
Does living without a gallbladder carry a risk of stones reforming?
Living without a gallbladder does not directly increase the risk of stone reformation, but other conditions can still promote stone formation within the bile duct itself.
How can gallstones be eliminated without surgery?
Currently, there are no highly effective non-surgical methods for eliminating gallstones. The effectiveness of medication-based dissolution therapy remains quite limited.
What symptoms indicate that I might need gallbladder surgery?
If you experience sharp pain, recurrent biliary colic, persistent nausea, jaundice (yellowing of the skin and eyes), or other signs of complications such as infection, you should seek evaluation from a doctor regarding possible surgery. Physicians will base their recommendation on the severity and frequency of your symptoms.
What dietary precautions are needed after gallbladder surgery?
After surgery, it is generally recommended to follow a light, low-fat diet for a few weeks. A normal diet can typically be gradually reintroduced, but it is important to avoid very fatty or heavy foods that could cause discomfort. Specific recommendations should always be discussed with your doctor.
Can diet influence gallstone formation?
A diet high in fat and sugar can contribute to gallstone formation. It is advisable to follow a balanced diet, low in saturated fat and rich in fruit, vegetables, and whole grains, in order to support gallbladder health.
Sources and references
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). “Gallstones”. niddk.nih.gov
- American Gastroenterological Association (AGA). gastro.org
- Wang, J., et al. “Fruit and vegetable consumption and risk of gallstone disease: a meta-analysis”. National Center for Biotechnology Information (NCBI). ncbi.nlm.nih.gov
- Bodmer, M., et al. “Statin use and risk of gallstone disease followed by cholecystectomy”. American Journal of Epidemiology. academic.oup.com
- Mayo Clinic. “Gallstones”. mayoclinic.org
- American College of Surgeons. “Cholecystectomy”. Patient education resources.
