To better understand what gallstones are, we need to discuss the role of the gallbladder and the bile ducts.
Contents of this article:
Fast facts on gallstones
Here are some key points about gallstones. More detail and supporting information is in the main article.
- the gallbladder is a small organ located on the underside of the liver
- stones can form when there is a chemical imbalance in the gallbladder
- overweight and obese people are more likely to develop gallstones
- experts believe a low-fat, high-fiber diet may help prevent gallstones
What is the gallbladder?
The gallbladder is a small sac located on the right-hand side of the body, on the underside of the liver.
Bile, also called gall, is a greenish-brown liquid, produced by the liver. Bile is stored and concentrated in the gallbladder. It enters the small intestine via the bile ducts (narrow tubes) to facilitate digestion, mainly of fats.
Every time we eat, bile is released into the intestines.
Gallstones: What are they?
When the chemicals in the gallbladder - cholesterol, calcium bilirubinate, and calcium carbonate - are out of balance, gallstones may form.
There are two main types of gallstones:
- Cholesterol gallstones - these may form if there is too much cholesterol in the bile. They are the main type of gallstones in the United Kingdom and United States.
- Pigment gallstones - these form when the bile has too much bilirubin. They are more common among patients who have liver disease, infected bile tubes, or blood disorders, such as sickle-cell anemia.
Gallstones causes and risk factors
Experts are not completely sure why some people develop the chemical imbalance in their gallbladder that causes gallstones, while others do not.
However, we do know that gallstones are more common among overweight/obese people, especially women. A study revealed that a bulging midriff almost doubles a woman's chances of developing gallstones and the need for surgery to remove them.
Obese children have a considerably higher risk of developing gallstones, compared with kids of healthy weight; researchers from Kaiser Permanente reported in the Journal of Pediatric Gastroenterology & Nutrition (August 2012 issue).
Others at risk include:
- women who have been pregnant
- family history
- people who have recently lost lots of weight
- intentionally losing weight rapidly and then regaining it may increase men's risk for gallstones later in life
- women taking oral contraceptives
- being sedentary
- women undergoing high-dose estrogen therapy
- people with a close relative who has had gallstones
- a study revealed that a gene variant significantly increases the risk of developing gallstones
- people whose intake of dietary fat is high
- twice as many women get gallstones than men
- people over 60 years of age
- native American Indians
- people who take statins (cholesterol-lowering drugs)
- people with diabetes
Additionally, hormone replacement therapy (HRT) for women during the menopause is linked to a higher risk of gallbladder problems. A study found that HRT administered by skin patches or gels poses a smaller risk than HRT given orally.
The majority of people with gallstones experience no symptoms at all. This is because the stones stay in the gallbladder and cause no problems.
Sometimes, however, gallstones may lead to cholecystitis (inflamed gallbladder).
Gallbladder inflammation symptoms
The primary symptom is pain that comes on suddenly and quickly gets worse. This pain can occur in the right side of the body, just below the ribs, between the shoulder blades, or in the right shoulder.
Other symptoms include:
- pain on the right-hand side of the body, just below the ribs
- back pain between the shoulder blades
- pain in the right shoulder
Other possible symptoms can occur in association with complications:
Biliary colic - When a stone gets stuck in the opening of the gallbladder, and will not easily pass through, the contraction of the gallbladder may cause severe pain. When this happens, the patient may experience biliary colic - a painful condition.
The pain is felt in the upper part of the abdomen, but can also exist in the center or to the right of the abdomen. Pain is more common about an hour after eating, especially if the patient has had a high-fat meal. The pain will be constant and last a few hours, and then subside. Some patients will have non-stop pain for 24 hours, while others may experience waves of pain.
Infection - if the gallstones have caused a gallbladder infection, the patient may have a fever and experience shivering. In the majority of gallstone infection cases, the patient will be hospitalized and have the gallstone surgically removed.
Jaundice - if the gallstone leaves the gallbladder and gets stuck in the bile duct it may block the passage of bile into the intestine. The bile will then seep into the bloodstream, and the patient will show signs of jaundice - the skin and the whites of the eyes will be yellow.
In most cases, this complication will require the surgical removal of the gallstone. For some patients the gallstone eventually passes into the intestine.
Pancreatitis - if a small gallstone passes through the bile duct and blocks the pancreatic duct, or causes a reflux of liquids and bile into the duct, the patient may develop pancreatitis.
In many cases, gallstones are discovered by accident when the patient is being treated for something else. A doctor may suspect gallstones after a cholesterol test, an ultrasound scan, a blood test, or even an X-ray.
Blood tests may be used to look for signs of infection, obstruction, pancreatitis, or jaundice.
A dye is either injected into the blood stream so that it concentrates into the bile ducts or gallbladder, or it is inserted straight into the bile ducts using an endoscope (ERCP - endoscopic retrograde cholangiopancreatolography). The dye shows up on X-rays. ERCP is also used to locate and remove stones in the bile duct.
The doctor will then be able to look at the X-rays and identify possible gallbladder or bile duct disorders, such as pancreatitis, cancer of the pancreas, or gallstones. The X-rays will indicate to the doctor whether the dye is going to where it should go - i.e. the liver, bile ducts, intestines, and gallbladder. If the dye does not move into one of these areas, it generally means that the gallstone is causing a blockage. An expert will have a better idea of where the gallstone is located.
This is a non-invasive X-ray that produces cross-section pictures of the inside of the human body.
Cholescintigraphy (HIDA scan)
A small amount of harmless radioactive material is injected into the patient. This is absorbed by the gallbladder, which is then stimulated to contract. This test may diagnose abnormal contractions of the gallbladder or an obstruction of the bile duct.
Gallstones are only treated if they have caused gallbladder inflammation, blockage of the bile ducts, or if they have moved from the bile ducts into the intestines. Patients who are treated are generally put on a low fat diet.
Cholecystectomy means the surgical removal of the gallbladder. This is usually performed with keyhole surgery (minimally invasive surgery). Keyhole surgery is not possible for about 10 percent of patients who need open cholecystectomy; they will have open surgery instead.
With open cholecystectomy a large cut is made in the patient's abdomen. Patients who undergo open surgery require a longer hospital stay and recovery time. If a patient's gallbladder is severely inflamed he/she will require open surgery.
For a large proportion of patients who undergo a cholecystectomy, gallstones come back within a year; to help prevent this, many patients are given urosdeoxycholic acid (the acid found in bile). Urosdeoxycholic acid lowers the cholesterol content of bile, making it less likely that stones will form.
If the gallstone is made of cholesterol it can sometimes be slowly dissolved with ursodeoxycholic acid. This type of treatment, known as dissolution, may take up to 24 months to be effective. It is not as effective as surgery, but is sometimes the only choice for patients who cannot have a general anesthetic.
Endoscopic retrograde cholangiopancreatolography
In some rare cases, when a patient cannot have surgery or ursodeoxycholic acid, he/she may undergo endoscopic retrograde cholangiopancreatolography (ERCP), which requires a local anesthetic. A flexible fiber-optic camera (endoscope) goes down the patient's mouth, through their digestive system and into the gallbladder. An electrically heated wire widens the opening of the bile duct; the stones are removed or left to pass into the intestine.
Ultrasonic shock waves are aimed at the gallstones, which break them up. If they become small enough they can then pass safely in the patients stools. This type of treatment is uncommon and is only used when there are few gallstones present.
If the bile duct or duodenum are blocked by gallstones, the flow of digestive juices to the pancreas may be blocked, this can cause jaundice and acute pancreatitis. Treatment usually involves the surgical removal of the gallbladder.
If is common for people who have had their gallbladder removed to experience feelings of bloating and indigestion, especially when they have a high-fat meal. Some may pass stools more often than before.
How to prevent gallstones
Vegetarians have a lower risk of developing gallstones.
Some factors that increase the risk of developing gallstones, such as age, sex and ethnic origin cannot be altered.
However, it is possible that having a vegetarian diet may reduce the risk of developing gallstones. Vegetarians have a significantly lower risk of developing gallstones, compared with people who eat meat.
Many experts say that a diet low in fat and high in fruit and vegetables, including plenty of dietary fiber, may help protect people from developing gallstones.
Controlling bodyweight may also help prevent the formation of gallstones. However, crash dieting and rapid weight loss increase the risk of developing gallstones.
Can we live without our gallbladder?
Fortunately, we can live without our gallbladder. The liver produces enough bile to digest a normal diet. If a person's gallbladder is removed, the bile reaches the small intestine from the liver via the hepatic ducts, rather than being stored in the gallbladder.
A small proportion of patients who have had their gallbladder removed will experience softer and more frequent stools for a while because their bile flows into the small intestine more often.